To find ghost types without evidence you HAVE TO be spatially aware (you can also use this guide for 1, 2 or even 3 evidence, if you just want to ditch the need for it). Without knowing everything that is going on around you you cannot do this. You need to always be listening, remembering, and quick thinking. Here are some key points and terms you need to know before beginning.

SANITY DRAIN

Sanity is what determines whether or not a ghost can hunt you, most ghosts not being able to hunt until the average sanity reaches below 50%. Sanity drains at different speed depending on the map you are on, and the ghost you are investigating. In multiplayer you drain double sanity to what you do in singleplayer, and in setup phase you will drain at 3/4 speed. Normal drain speed without accounting for these factors is:
.12%/s, 10% every 83s for small maps
.08%/s, 10% every 125s for medium maps
.05%/s, 10% every 200s for large maps

Sanity drain speed also speeds up and slows down in different difficulties

1x Amateur
1.5x Intermediate
2x Professional and above

If you have a custom gamemode it will tell you exactly how much % of usual speed it will drain at.

If the lights are on in the room you are in, or you are holding a lit candle, you will lose no sanity (unless it does and event or is a specific ghost type)

If a ghost throws an item and it hits you, you will lose 5% sanity.

GHOST EVENTS

Ghost events are the ghost showing itself, or doing extreme paranormal activity (blowing a lightbulb), during these events your flashlight will flicker and so will any lights/electronics around the ghosts point of manifesting. There are different types of events, each having different sanity drain and meaning.

Walking event
The ghost will materialise and walk towards a selected target, if it reaches it's target it will breathe in their ear and their sanity will drain 10%.

Air ball event
There will be no ghost but instead a ball of vapour, or mist, will chase someone, if it reaches them it will whisper in the targets ear and drain their sanity by 10%. This event CANNOT be done by an Oni.

Light event
The ghost will make a light flicker and make noises over a couple of seconds until it blows while the ghost shows itself nearby, this light will be unusable for the rest of the round. Sanity drain 10%.

Standing event
The ghost will appear and sing or make sounds on the spot, walking into the ghost will drain your sanity by 10%, however if it is a Phantom, just looking at it will drop the 10% sanity.

GHOST SPEED and LINE OF SIGHT

Normal ghost speed is 1.7m/s or 2 steps per second (1 step = 0.85m), if a ghost gets line of sight on you (sees you) it will increase over 13 seconds to a max speed of 1.65x it's base speed[/b] (it does slow down again if you are out of line of sight, however it is much slower to decrease than increase). Some ghosts do not speed up in line of sight, usually these ghosts have special conditions they are under and will be slower/faster than normal without line of sight anyway. Certain ghosts go slower or faster depending on certain conditions, making listening to hunts one of the best ways to identify the ghost. If you want to hear the exact speed you can use a metronome (there are youtube videos of all speeds of metronome) to simulate the ghost speed. The equation for a ghost's bpm is the ghosts m/s x 60 then the product of that divided by 0.85. Normal ghost speed is 120bpm (or 2 beats a second).

FLICKER SPEED

When hunting a ghost is not always visible. It will flicker in and out of view, most ghosts stay invisible from 0.1-0.92 seconds before reappearing again.

SMUDGE STICKS

Smudge sticks are an extremely useful item, they can be used on the ghost to blind it during hunts, forcing it to wander around aimlessly for 6 seconds (12 seconds if it's a Moroi), and breaking line of sight until the time is up, at which point it will hunt normally again. You can even walk through the ghost while holding a lit smudge stick and it will not be able to kill you. You can also use smudge sticks to prevent hunts. Smudging the area (favourite room or where it is manifesting) of the ghost will prevent it from hunting for 90 seconds (unless it is a spirit or demon, spirit will not be able to hunt for 180 seconds, while demon can hunt after just 60 seconds).

LOOPING

Looping is a method players use to see the ghost for extended periods of time without at risk of being killed. There is line of sight looping and out of line of sight looping. Line of sight looping is useless if you want to find the ghost type since it will speed up in line of sight (unless a Thaye or Hantu), therefore you cannot know what it's base speed is. Non line of sight looping is the more useful option because it's less dangerous and more effective (since you can see the ghost and if done correctly it will remain at it's original speed). Not looping is better than looping badly. If you do not know how to loop yet, don't attempt it whilst in a genuine game, it's better to just find a hiding spot to listen from. If you do it wrong it is likely it will speed up to the point of no return and force you to waste a smudge or else die. As someone who plays in multiplayer often please do not be that person who says they can loop and then goes and kills everyone by looping it wrongly.

Here are all of the ghosts and their special characteristics.

DISCLAIMER: The "Other" section cannot be heavily relied upon, only useful if you're stuck between 2 ghost and you just want to make an educated guess or if you're trying to find what type of ghost you should do a proper test for. Also most of this information is off the top of my head so I apologise if not 100% accurate.

Risk of hunt: How high the risk of it hunting is (not the sanity it hunts at but the risk of it hunting at any given time).

Risk during hunt: How dangerous the ghost is during the hunt.

Loopability: How how it is to loop the ghost around a regular looping spot.

Hunting sanity: 50%

Speed: 1.7m/s

Risk of hunt: 5/10

Risk during hunt: 5/10

Loopability: 5/10

Special abilities/Characteristics:
Spirits do not have any special abilities. However you can tell if it is a Spirit by Smudging it while below hunting sanity and seeing how long it take for it to hunt.

Testing: If it's a Spirit it won't be able to hunt for 180 seconds after smudged, if it takes this long it is most likely a Spirit since most ghosts can hunt after only 90 seconds.

Other:
Another small characteristic of the Spirit is it seems to do an event when you first enter the ghost room, all ghosts can do this, but Spirits seems to usually do it since it is a territorial ghost.

Hunting sanity: 50%

Speed: 1.7m/s

Risk of hunt: 5/10

Risk during hunt: 6/10 (Possible to get spawned on top of)

Loopability: 5/10

Special abilities/Characteristics:
Wraith's special ability is to go through walls and not touch the ground (even though they do make footstep sounds while hunting).

Testing:
A good way to tell if it is a Wraith is to put a Motion sensor aiming through the doorway of the ghost room, then placing salt along the threshold of the doorway. If the ghost triggers the Motion sensor but does NOT step through the salt, it is a Wraith. Wraiths cannot step through salt even if they go right through it, while all others usually leave footsteps in the salt if walking by.

Other:
Wraiths have a random chance to teleport within 3m of a random person, giving off EMF. This can be particularly lethal since they can do this at the start of a hunt.

Hunting sanity: 50%

Speed: 1.7m/s

Risk of hunt: 5.5/10 (slightly higher sanity drain)

Risk during hunt: 6/10 (hard to see)

Loopability: 4/10 (hard to see)

Special abilities/Characteristics:
Phantoms have higher sanity drain during events, if you look at a Phantom it will drain 10% sanity, but with most other ghosts you have to actively walk in to it to lose sanity. Phantoms disappear during events if you take a photo of them, and during hunts if you take you photo, you will stop hearing your heartbeat if the ghost is nearby for that hunt.

Testing:
Because Phantoms disappear when you take a photo of them you can actually check using the photo album. If you take a picture of the ghost during an event and it disappears, then look in your photo album. If it says star ghost photo down the bottom, but there is no ghost in the picture or interference with the camera, then it is a Phantom (Example on right).

Another way to see if it is a Phantom, is it's flicker speed. Normal ghosts flicker invisible for 0.1-0.92 seconds during hunts, but the Phantom goes invisible for 0.7-1.92 seconds, making it much harder to see. There is a visible difference between normal ghosts and a Phantom. (Youtube video on the left shows Phantom blinking speed)

Other:
Phantoms can spawn on top of you when they begin hunting, no matter what room you are in.

Phantoms do Standing events a lot more than average ghosts.

Hunting sanity: 50%

Speed: 1.7m/s

Risk of hunt: 5/10

Risk during hunt: 5/10

Loopability: 5/10

Special abilities/Characteristics:
Poltergeists throw things a lot. It's ability is to throw several things at once. It has a 100% chance to throw something every 0.5 seconds during a hunt while all other ghosts only have a 50% chance.

Testing:
The test for a Poltergeist is commonly known as a Polter Pile. The way to do this is to gather throwable items into a pile in a commonly roamed area, if the ghost walks through this and knocks all of them out of them way all at once, it is a Poltergeist. This does not have a 100% chance of happening to watch several times if you can. If you want a higher chance of it walking though, you can wait for it to hunt and listen for it to walk through the pile, this is known as a "Polter Bomb" because the sound of all the objects being thrown at once sounds like an explosion. (Video of Polter bomb on the right)
Tip:
A good tip for Poltergeists and the game in general; if you are in multiplayer and someone has died, you can ask them to make a Polter Pile if you suspect it may be a Poltergeist (since dead players can pick up and throw the same things ghosts can), and you can do it yourself too if you are the dead one.

Hunting sanity: 50% (explained below)

Speed: 1.7m/s

Risk of hunt: 5/10

Risk during hunt: 6/10 (may get spawned on top of)

Loopability: 5/10

Special abilities/Characteristics:
A Banshee will single out a player and follow them around, It can hunt that player when they reach below 50% sanity (team average does not matter).

In singleplayer the target's obviously got to be you, but in multiplayer the target is randomly selected and the Banshee will only be able to hunt, and event on that target unless the target dies, in which the Banshee will reselect a target out of the living players. If the target is not in the house, the Banshee will act like a normal ghost and will be indiscriminate whilst hunting and eventing.

Banshees will usually start hunting right on top of their target since they follow them around, so crucifixes are almost useless, unless the target is in the ghost room or holding a crucifix.

Testing:
Banshees give off a special parabolic sound which makes them easy to identify. It occasionally screams through the paramic, with only a 1/4 chance to occur. No other ghost (except The Mimic if it is mimicking a Banshee) can make this parabolic sound. (Youtube video showing what it sounds like on right)

Another way to test is to see if it is following someone. Get everyone to walk about the map, away from the ghost room. If someone keeps hearing it interacting with things around them it is probably a Banshee and following them. If you want to be 100% sure with this type of identifying, you get the target identified and wait for it to hunt. Once it starts hunting you can see if it switches targets while hunting. You can do this by getting it to chase the target for a second but then smudging or getting the target to hide, then have someone else nearby who is now the only person in line of sight (make sure they have a smudge in case it isn't a Banshee), if the ghost does not go for them (make sure the 6 seconds smudge time is up if you used smudge) then it is a Banshee. As long as the target stays in the map, everyone else should be free to walk around while it is hunting, and even walk through it. This only works in multiplayer.

If you are in multiplayer and the ghost does 2 walking events towards 2 different people without either of them leaving the house, while everyone is in the house, then it can not be a Banshee.

Other:

If the ghost is hunting and someone walks through without dying it without it being smudged, then it is a Banshee.

If you notice the ghost is hunting away from it's room a lot, or following a certain person around, consider tesing for Banshee.

There is lots of speculation about Banshee's targeting behaviour, the behaviour mentioned above could be incorrect but it's what fits best from experience.


Tips:
If a Banshee does a Walking ghost event, it will always walk towards it's target, making this an easy way to identify who it is following.

Hunting sanity: 50%

Speed: 1.7m/s, 2.5m/s line of sight with breaker on

Risk of hunt: 6/10 (It can remove 25% sanity at random)

Risk during hunt: 7/10 (speeds up quickly if breaker is on)

Loopability: 5/10 (should remain unaffected by ability if looping correctly)

Special abilities/Characteristics:
The Jinn uses the breaker to charge it's abilities, if the break is off they cannot use them. If the breaker is on, during a hunt if a Jinn gets someone in line of sight and they are more than 3 metres away, they will speed up to catch up to them.

The other ability of the Jinn is to have a slight chance to drop 25% sanity of anyone in the ghost room while the breaker is on.

Testing:
The best way to test for a Jinn is to have the breaker on and wait for it to hunt with a smudge ready. When it begins to hunt let it get a line of sight on you. If it speeds up immediately to 2.5m/s (just under 3 paces a second), but then slows down to normal speed (1.7m/s or 2 paces a second) around 4 paces (3 metres) from you, then it is most likely a Jinn.

Put an EMF on top of the breaker with the breaker on. When the Jinn uses it's ability it will try to turn the breaker off but it can't so instead it will give off EMF 2. The Jinn is the only ghost that can't turn off the breaker and the only one that can give off EMF without changing the breaker's status or interacting with the door.

Other
Jinns will be slightly less active when the breaker is off.

A much less reliable way to test for a Jinn listen to it hunt without giving it line of sight. This test does not need the breaker on. If it double steps every 3 steps it may be a Jinn. This does happen sometimes, it may be making waypoints to speed up from if it sees a player. However this test is not at all reliable and should only be used as a last resort or if the breaker is set it broken in your game mode and there's no other way to figure it out.

Hunting sanity: 40% or 60% (explained below)

Speed: 1.7m/s

Risk of hunt: 5.5/10 (be mindful of the lights)

Risk during hunt: 5/10

Loopability: 5/10

Special abilities/Characteristics:
Mares can hunt a lot more easily in the dark, but if a light is on it will make it harder. Mares can hunt at 60% if the lights are off in the ghost room, but if the lights are on it can only hunt at 40%. If you are below 40% sanity it will hunt as normal and the light won't affect it at all (except it might have the tendency to start hunting in a place out of the light).

Testing:
Mares special ability is to flick off a light as soon as you turn it on (in the ghost room). Just flick the light on and off and on and off and see if it flicks it straight off when you turn it on (this has a small chance of happening so keep trying), if it flicks it off as soon as you turn it on it is a Mare. The breaker doesn't have to be on for this to work (though it does make it tough because you can't be sure which way is on and which way is off if you lose track).

You can also test what sanity it hunts at with the lights in it's room on and off. If it hunts at 60% with the lights off, turn the lights on in the room and see if it still hunts. Since your sanity stays roughly the same with the lights on around you, you shouldn't go below 40% as long as you don't let it drain your sanity during events. If it does not hunt while you keep the lights on and you are above 40% then it is probably a Mare.

A way to test if it's NOT a Mare is if it turns the lights ON. Mares cannot turn on the lights, the only ghost that can't. If you have a tricky room with no light switch, try and find a TV remote and place it in the room. If it uses the TV remote to turn on the TV, it cannot be a Mare since the TV acts as a light, and the remote a light switch.

Hunting sanity: 50%

Speed: 1m/s, 3m/s line of sight

Risk of hunt: 5/10

Risk during hunt: 8/10

Loopability: 0/10

Special abilities/Characteristics:
Revenents speed up massively in line of sight (if they hear or detect you too), faster and more instant than any other ghost. If a Revenent sees, hears, or detects you it will speed up to 3m/s or around 3.5 paces a second. When they no longer detect you, they will go slower than any other ghost (except Deogen when up close) with a speed of 1m/s or just over 1 pace a second.

Testing:
Revenents go slower than any other ghost while you are hiding, so if the ghost seems very slow and isn't a Deogen (see Deogen info to understand why) then it is most likely a Revenent.

A sure way to know if it's a Revenent is to get a smudge and enter the map, then wait for it to hunt. Once it starts hunting, call it over and turn on electronics. It will be slow (1m/s) when it doesn't sense you, but when it sees you, it will go very very fast (3m/s) almost instantly. Once it's close to you, smudge it and if it's a Revenent it should go back to slow (1m/s again) for the 6 seconds blinded by smudge. Other ghosts do speed up in line of sight and slow down once you are out of it, but none do it as instantly as a Revenent, and that's why this is a good way to test for one.

Hunting sanity: 35%

Speed: 1.7m/s

Risk of hunt: 1/10

Risk during hunt: 4/10 (you can't get spawned on)

Loopability: 5/10

Special abilities/Characteristics:
Shades are very hard to find since they do so little activity, and if you do find the ghost room they will completely cease activity whilst you are in it, as well as not being able to start a hunt while you are in the ghost room.

Testing:
Get your sanity below 35% and wait in the ghost room. If the ghost does not hunt while you are in the room it is probably a Shade. You can test this further by leaving the room and seeing if it hunts, if it hunts right after you leave the room then it is a Shade.

Hunting sanity: 70% or Any (explained below)

Speed: 1.7m/s

Risk of hunt: 9/10

Risk during hunt: 5/10

Loopability: 5/10

Special abilities/Characteristics:
Demons can hunt at 70% sanity, but they have a random chance to hunt regardless of any sanity. Crucifixes are more effective on Demons and cover a wider area. Smudges only prevent Demons from hunting for 60 seconds instead of the usual 90 seconds.

Testing:
Get your sanity relatively low to ensure that there is a guaranteed hunt, and remove all crucifixes from the house. Now smudge the ghost room and start a timer. If the ghost hunts within 60-85 seconds it is a Demon (you have to be in the house for it to hunt so stay inside), if it hunts above 90 seconds it is probably NOT a Demon.

Another, less reliable way, to see if it is a Demon is to time the space between hunts. Every ghost other than the Demon has to wait 25 seconds between hunts, but Demons only have to wait 20 seconds. This can be buggy however so don't lock in Demon without further testing.

Other:
While there is a crucifix in the ghost room, Demons will tend to become a lot less active.

Hunting sanity: 50%

Speed: 1.7m/s

Risk of hunt: 5/10

Risk during hunt: 5/10

Loopability: 5/10

Special abilities/Characteristics:
The Yurei has the special ability to slam a door and drain the sanity of anyone within 7.5m by 15%. The weakness of the Yurei is that smudging it, no matter it's location, will send it back to it's room and trap it there for 60 seconds.

Testing:
When the Yurei uses it's ability it will close the door in a certain way, it can make it go from fully open to completely shut, which no other ghost has the force to do. To see if the ghost is a Yurei, check your sanity and bring a candle to hold into the ghost room, fully open a door in the room, and stand next to it. If the ghost slams the door from fully open to shut, then it is a Yurei using it's ability. You can double check this by going back to the van and checking your sanity, if it is 15% lower than when you checked before, it is a Yurei since the candle should have kept your sanity the same.

If the ghost touches the front door it is a Yurei.

Hunting sanity: 50%

Speed: 1.7m/s

Risk of hunt: 5.5/10 (higher sanity drain)

Risk during hunt: 4.75/10 (more visible)

Loopability: 5.5/10 (more visible)

Special abilities/Characteristics:
Oni's do events a lot more than other ghosts and tend to make their events look like hunts. When doing an event they will drain 20% sanity upon collision instead of 10%. Onis are the only ghost that cannot do an Air ball event. They also flicker less then normal ghosts during hunts, only invisible for about half a second before reappearing (shown on right), which makes them easy to identify during hunts.

Testing:
If you suspect the ghost may be an Oni, watch it hunt with a smudge and see if it is more solid than usual ghosts, it will be obvious if it is an Oni since they only go invisible while hunting for 0.01-0.5 seconds during hunts instead of the usual 0.1-0.92 seconds (Watch the video on the right if unsure).

Onis cannot do Air ball events, meaning you can rule out Oni if you get one (Air ball event shown on the left).

Hunting sanity: 50% or 80% if talking nearby

Speed: 1.7m/s

Risk of hunt: 7.5/10

Risk during hunt: 3/10 (cannot detect electronics or voices unless at point blank)

Loopability: 3.5/10 (may stop following you around the loop because it can't detect you)

Special abilities/Characteristics:
Yokais are the earliest hunters (other than if a Demon uses it's ability), if someone is talking nearby it, it has a chance to hunt below 80%. If no one is talking near it, it will hunt at normal sanity (50%). Yokais have low sensory, only able to sense held electronics and players talking from 2.5m away (most ghosts can sense talking from 9m and electronics from 7.5m). Yokais still have a normal electronics interference range of 10m.

Testing:
Hide in the back of a room along a hallway or somewhere out of the way and where the ghost can't get line of sight on you (Yokai has normal line of sight). You can also just do this in a hiding spot when the ghost is within 9m. Open your mic while the ghost is hunting. After a second or 2 close it again, if the ghost does not come to you and you're sure it was within 3-9m of you when your mic was on, it is a Yokai, since all ghosts go to where they last sensed a mic on even if it get's turned off, and every other ghost would have sensed you from that distance (Video on right showing Yokai's sensory during a hunt).

Hunting sanity: 50%

Speed: 1.4m/s-2.7m/s (depending on temperature)

Risk of hunt: 5/10

Risk during hunt: 9/10 in a cold room, 2/10 in a warm room

Loopability: 3/10 in a cold room, 8.5/10 in a warm room

Special abilities/Characteristics:
Hantus like the cold and are much more aggressive when the ghost room is cold. Hantus will speed up in cold areas while hunting and slow down in warmer areas. With non-rainy weather and the breaker on, a Hantu will move at 1.4m/s (1.5 paces a second) while hunting. With the breaker off it will move at about 2.1m/s (just under 2.5 paces a second). When it enters a freezing room (usually the ghost room), it will travel at 2.7m/s (a bit over 3 paces a second). Luckily if you are using a zero evidence custom, the ghost room cannot reach freezing temperatures so it will not get this fast. However in 1-2 evidence customs, freezing temperatures is a forced evidence for the Hantu. Hantus do not speed up in line of sight. They are the only ghost that cannot turn the breaker on.

Testing:
Turn the breaker on and wait for a hunt. When it starts hunting, just listen from a hiding spot. If it sounds slow it may be a Hantu. Once the hunt ends turn the breaker off and listen to it hunt. If it's fast now you are most likely dealing with a Hantu. You can repeat this process of turning the breaker on and off and listening to it hunt to be sure.

Hantus will have an inconsistent speed when the breaker is off, going around 2.1m/s in most rooms, then speeding up in the ghost room where it usually makes it a lot colder (even if not freezing). If you have no electronics nearby (ruling out Raiju) and you hear it going at different speeds during the same hunt, it is a Hantu, since only Raiju, Hantu, and Deogen can change speeds during a single hunt without line of sight, and if it was a Deogen it would have found you (read the Deogen and Raiju profiles if you do not know their characteristics).

Other:
Hantus make a very large area around their ghost room very cold, very quickly.

Hunting sanity: 50%

Speed: 1.7m/s

Risk of hunt: 5/10

Risk during hunt: 5/10

Loopability: 5/10

Special abilities/Characteristics:
Goryos cannot change their favourite rooms, no matter the change room chance. They will also not do D.O.T.S in front of a person or if there is a person in the room, making D.O.T.S only visible on cams. D.O.T.S is a forced evidence for Goryos so if you have 1 or more evidences and there are no D.O.T.S, it cannot be a Goryo.

Testing:
The only real way to know if it's a Goryo in 0 evidence is by ruling every other ghost out.

In 1 or more evidence games if you get a video camera and stand outside the room where dots are placed and you've seen on cams that it's done D.O.T.S, see if it does D.O.T.S on the video camera while also looking at the D.O.T.S without the camera. Make sure you are outside the room because a Goryo won't do D.O.T.S if you are in the room. If the ghost does D.O.T.S on the camera but not directly in front of you without the camera, then it is a Goryo.

Alternatively if the ghost does D.O.T.S in front of you with no camera, then it can't be a Goryo.

If the ghost moves rooms you can rule out Goryo.

If you have "change ghost room" set to high on a Custom, or if you are in Nightmare or a above, and it hasn't changed rooms once over a long period, and there are no characteristics that it is showing, it may be a Goryo.

Other:
Goryos do not roam very far from their favourite room while not hunting.

Hunting sanity: 50%

Speed: 1.7m/s

Risk of hunt: 5/10

Risk during hunt: 6/10 (hard to hear)

Loopability: 5/10

Special abilities/Characteristics:
Mylings are very quiet hunters, they can only be heard from 12m away. This can make them especially dangerous to new players as they will not hear it coming until it is too late. Mylings when not hunting however, are very loud and vocal. They make sounds through the parabolic microphone regularly and are very loud during events.

Testing:
Get an electronic of some sort and place it on the floor of a hiding spot (I'd advise D.O.T.S). Wait for the ghost to hunt. When it begins hunting see whether you can hear it from normal range. You can hear most ghosts from 20m while you can hear the Myling from only 12m. So if your electronic flickers (which means the ghost is within 10m) then stops flickering and you instantly hear it's footsteps fading out (or barely heard it's footsteps while it is in 10m range), then it is a Myling because if the footsteps fade out right after it leaves electronic interference radius, it probably means it's fading out at 12m. (Myling hunt on the right).

Hunting sanity: 60% or Any sanity if ability used

Speed: 1.7m/s

Risk of hunt: 7/10

Risk during hunt: 5/10

Loopability: 5/10

Special abilities/Characters:
Onryos are early hunters without their ability, but cannot hunt if there is a flame in their ghost room. If 3 flames are blown out by an Onryo (doesn't have to be all at once), it will start a hunt within the next couple of seconds if you do not re-light the flame within that period.

Testing:
Get 3 candles and a crucifix and place them in the ghost room (candles lit), then wait. If the ghost blows out all 3 candles (does not have to be all at once), then after a couple of seconds it burns the crucifix, it is probably an Onryo. Test this a couple of times if you can as it may have just been a coincidence. If it does the same thing again then it is an Onryo.

Get a candle and a crucifix and place them right next to each other. If the candle remains lit but the ghost burns the crucifix then it cannot be an Onryo.

If you have low sanity and you have a candle in the ghost room that you are keeping alight and the ghost isn't hunting even though you have low enough sanity for any ghost to hunt, then it's probably an Onryo. You can double check this by letting the candle stay blown out and seeing if it hunts then. If it hunts while you are in the room (ruling out shade) and you let the candle stay blown out, then it is an Onryo.

Hunting sanity: 50%

Speed: 1.5m/s and 1.9m/s (depending on which Twin it is)

Risk of hunt: 5/10

Risk during hunt: 6/10 (unpredictable speed and location)

Loopability: 5.5/10 (chance of it being fast)

Special abilities/Characteristics:
The Twins are basically 2 ghosts (though they have the same ghost model). There is a base ghost and a decoy ghost. The base ghost is slow, with a speed of 1.5m/s (less than 2 paces a second) but the decoy ghost is fast, with a speed of 1.9m/s (more than 2 paces a second). The decoy ghost will have a different ghost room nearby to the proper ghost's room. Either of them can initiate a hunt (though the decoy ghost has a slightly lower chance to do so). Decoy ghost can only give EMF evidence, whilst the base ghost gives all 3.

Testing:
Simply listen to it hunt. If you hear it going a little slower than a normal ghost, then in a different hunt going a little faster than a normal ghost, then you hear it keep changing between those 2 speeds, then it is The Twins. (Speeds shown below)

Hunting sanity: 65% (if electronics in ghost room, otherwise 50%)

Speed: 1.7m/s, 2.5m/s when near electronics

Risk of hunt: 7/10

Risk during hunt: 9/10

Loopability: 2/10 (impossible if you use electronics to let it track you)

Special abilities/Characteristics:
Raijus harness electricity to make themselves faster. When near electronics, not only do they have a higher chance to hunt, but if near electronics when hunting, the Raiju will speed up from 1.7m/s to 2.5m/s. The proximity varies on different sized maps. They will speed up within 6m from electronics on small maps, 8m on medium maps, and 10m on big maps. Raijus also interfere with electronics from 15m away rather than 10m while hunting.

Testing:
Get an electronic of some sort and place it on the floor somewhere near a hiding spot (some electronics will not count unless placed, so make sure the electronic is on), so that you can pinpoint where it is while hiding. Go into your selected hiding spot and wait for a hunt. When it hunts, listen to see if it speeds up around where you placed the electronic. If it does, it's a Raiju.

Other:
Raijus will still speed up in line of sight and when electronics are on nearby and it has sped up already, it will still go even faster near them.

Raijus will make lights flicker a lot more than other ghosts, usually just by roaming.

Hunting sanity: 50%

Speed: 1.7m/s

Risk of hunt: 5/10

Risk during hunt: 5/10

Loopability: 5/10

Special abilities/Characteristics:
Obakes are shapeshifters, they can change to a different ghost model while hunting. They have a 6.66% chance of changing to a random different ghost model while flickering (as shown in video below).

Testing:
Watch the ghost hunt with a smudge stick, and see if it flickers to a different ghost. This is the only real way to identify and Obake with no evidence. Obakes will shapeshift about 2 times per hunt, so you should see it happen if you watch for long enough and it is an Obake.

If you have 1 evidence or more, Obakes leave a special type of fingerprints that have 6 fingers (1/4 chance to leave 6 fingers instead of 5). They are also the only ghost that does not have a 100% chance to leave fingerprints even if the fingerprint chance is set to 100%.

Fingerprints is a forced evidence for the Obake, so if you have 1 or 2 evidences on and neither is fingerprints, then it is not an Obake.

Other:
When shapeshifting the Obake may not make a footstep sound, I am not 100% on this however as I have not tested it properly.

Hunting sanity: Of the ghost it is mimicking

Speed: Of the ghost it is mimicking

Risk of hunt: 6/10 (unpredictable)

Risk during hunt: 6/10 (unpredictable)

Loopability: 6/10 (unpreditcable)

Special abilities/Characteristics:
The Mimic copies other ghosts, it's ability being to change what ghost it is mimicking. They while change at least every hunt and can often confuse and deceive. Mimics are the only ghost that have 4 evidences. They do Freezing temperatures, Fingerprints, Spirit box, and Ghost orbs. Ghost orbs don't count as an evidence in the journal though, more a characteristic, so when ticking off orbs in evidence it will blank out The Mimic but do not forget it is there.

Testing:
If you are in a zero evidence custom and you see ghost orbs then it is The Mimic, since ghosts can't give evidence and The Mimic is the only ghost that will show ghost orbs no matter what.

The Mimic will change what kind of ghost it is mimicking often, so if you hear it moving fast during a hunt one time, then slow next time, then some other speed or hunting characteristic the time after that, then it is a Mimic.

Other:
If you have all evidences on, they can also mimic special evidence characteristics like Obake fingerprints and Deogen Spirit box response, so if 2 of those characteristics specific to 2 different ghosts happen then it is a Mimic.

Hunting sanity: 50%

Speed: 1.5m/s-2.25m/s (depending on player sanity)

Risk of hunt: 4/10 (low activity until below 50% sanity)

Risk during hunt: 8/10 (fast at lower sanity)

Loopability: 2/10 (fast at lower sanity)

Special abilities/Characteristics:
Morois' speed depends upon the player's sanity (average if in multiplayer). When players are at 50% sanity, a Moroi will move at 1.5m/s while hunting. They will then increase their speed by 0.083m/s per 5% sanity lost until the player reaches 0% sanity, by which time the Moroi will move at 2.25m/s (about 2.5 paces a second) while hunting. Morois also place a curse upon a player if they get a response through spirit box or hear a sound through the parabolic microphone, when the curse is placed upon them, their sanity will drain at twice normal passive speed, and even begin draining when holding candle or in the light (not when outside map however). The curse will be removed if the player takes sanity pills. Morois are also affected by smudge sticks for longer while hunting, being blinded for 12 seconds instead of 6 seconds.

Testing:
If you are at 0% sanity and the ghost is going very fast (3 paces a second or 2.25m/s) and you have the breaker on and no electronics on nearby, then you may be dealing with a Moroi. The only ghosts that can move this fast consistently without line of sight are Moroi and Thaye. You can tell Moroi speed from Thaye speed, as Morois moves at 2.25m/s while hunting and Thayes at 2.75m/s (this is only at age 0, Thayes will slow down as they age, Thayes and Morois are sort of opposites but easy to confuse with each other if doing 0% sanity runs, so read Thaye profile to understand more). Thayes take so many steps a second that the sound of the previous footstep will be overlapped by the next. If you still cannot tell which it is, then grab a smudge and wait for a hunt in a hallway or similar. Once it hunts make sure it sees you. Once it sees you do not smudge until it is right next to you. If it speeds up in line of sight, it is a Moroi, since Thayes cannot speed up in line of sight. Thaye versus Moroi speed linked in Thaye profile.

If you are at 50% average sanity and the ghost hunts and you hear it going slow, it could be a Moroi. Morois go at 1.5m/s while hunting if the average sanity is at 50%. If you let your sanity get lower, and the ghost speeds up faster and faster as it gets lower, then it is a Moroi. You can double check this by taking some sanity pills and seeing if it goes slow again.

If you are not so confident with hunt speeds then an easier way to test for a Moroi is to utilise the curse (you can only do this if you have the sanity monitor on). Get a Paramic (or spirit box if you have evidence on) and try and get a Parabolic sound (or response). Once you do, go back to the van get a candle and ligher, and check your sanity. Go back into the map and make sure the candle stays lit. After a couple of minutes go back to the van. If your sanity has continued to lower while holding the candle then it is a Moroi as your sanity should stay the same while holding a candle (unless your sanity gets drained by a ghost event or Yurei ability).

Tips:
If you only have 1 or 2 evidence on and neither of them/it wasn't spirit box, then it can't be a Moroi as spirit box is a forced evidence for Morois.

Hunting sanity: 40%

Speed: 3m/s-0.4m/s

Risk of hunt: 4/10

Risk during hunt: 1/10 (if you know it's a Deogen), 8/10 (if you are hiding or cornered)

Loopability: 10/10

Special abilities/Characteristics:
Deogens can sense you wherever you are, when they begin hunting they will lock onto the nearest player and run towards them. They will move at 3m/s when over 6m away, and under 2.5m away they will move at 0.4m/s, between 6m and 2.5m they will be adjusting in between the 2 speeds.

Testing:
Deogens are the easiest ghosts to tell from one hunt, they will rush over to a targeted player and then slow down as they approach. When the ghost starts hunting, if you hear the ghost rush towards you and then slow down and get really slow when you start hearing your heartbeat, then it is a Deogen, in which case you need to leave any hiding spot you are in (this may be impossible by the time you realise it's a Deogen, so have a smudge stick if Deogen isn't ruled out or you suspect it may be one). You can easily escape a Deogen during hunts once you have figured out what it is since you can just loop it around a piece of furniture or similar. (Deogen hunt in video on bottom right)

Deogens give a special spirit box response that sounds like heavy breathing and has a 1/3 chance to happen. (Video on bottom left showing response)

Tips:
If you have 1 or 2 evidence on and neither of them/the evidence you get is not spirit box, it cannot be a Deogen because it has spirit box as a forced evidence.

Hunting sanity: 75% (lowers by 6% every time it ages)

Speed: 2.75m/s-1m/s (loses 0.175m/s every time is ages)

Risk of hunt: 9/10

Risk during hunt: 10/10 (if young), 1/10 (if old)

Loopability: 1/10 (if young), 10/10 (if old)

Special abilities/Characteristics:
Thayes are ghosts that age quickly in the presence of players. Every 1-2 minutes it will age if there is a player in the same room as it, if there is not a player in the same room as it, it will not age. If it fails to age it will only wait 30 seconds before trying to age again. When you first enter the map a Thaye will be age 0. The max Thaye age is age 10. They will go from a hunting speed of 2.75m/s (age 0) to 1m/s (age 10), and a hunting sanity threshold of 75% (age 0) to a hunting sanity threshold of 15% (age 10).

Testing:
An easy way to test if the ghost is a Thaye is to stay in the ghost room, (run out of the room to hide whenever it hunts) and let it age. If it is a Thaye it should start extremely fast then slowly get slower and slower, until you can outwalk it (it will only age if you are in the ghost room).

Thayes are the fastest ghost without line of sight, so just listen while it hunts, the steps sound like they're overlapping each other if it is an age 0 Thaye. Thayes will also not speed up in line of sight, so if you're not sure, get a smudge and see if it speeds up when it sees you while hunting. If it doesn't it is probably a Thaye (Video below showing Thaye speed and how you can distinguish from Moroi).

If you have a Oujia board on your contract then you can ask the ghost "How old are you". Remember what age it is and ask it again after a couple of minutes, and if it changes (gets older) then it is a Thaye.

Tips:
Cursed hunts are a very bad idea with Thayes.