I have examples!
Noise Goblin(Pizza Tower)(Replaces Rocketeers):Uses a bow to shoot pizza-slice shaped cutters.
Eggplant Farmer(Pizza Tower)(Replaces Kleers):Throws 3 hooks in a wide spread!
Octotorpedo(Splatoon series)(Replaces Kamikazes):Can leave a puddle of ink after exploding!
Salmonid Chum(Splatoon:Salmon Run)(Replaces Gnaars):Uses a pan to hit players
Salmonid Smallfry(Splatoon:Salmon Run)(Replaces Hoppers):Uses a spoon to hit players
Chuck(Spongebob:Battle for Bikini Bottom)(Replaces Harpies):Throws missiles at players
Jelly Roller(Spongebob:The Cosmic Shake)(Replaces Kleers):Charges at the player
Zum'tiloid(Zum'bul + Reptiloid)(Replaces Reptiloids):In addition to homing projectiles,these hybrids have 4 missile launchers!

The ideas are great! When making next update I might pick some of these if you add more description.

Sure,Thanks T&C!
Enemies from SeriousNorbo's New Enemies mod for SS3:BFE

• Reptalion(Replaces Gnaar):A green round creature with 4 bug legs!
  
• Magem's Skull(Replaces Harpy):A skull-headed being with an orb that makes it fly,and giving it ability to throw chainballs!
  
• Gunsaur Raptor(Replaces Arachnoid Juvenile):A Raptor with a machinegun on its head.
  
• Gunsaur Rex(Replaces Biomech Major):A giant skeleton T-Rex with a Rocket Launcher on its head!
  
• Selrunner(Replaces Kleer):This turquoise colored freak throws plasma projectiles at you,while leaping towards when close to you!
  
• Biocreol(Replaces Werebull):A car like cyborg that rams with a rolling crusher!
  
• Crate Warrior Duo(Replaces Biomech Minor):2 mesmarized brain guys driving a crate that fires lasers!
  
• Sirian Wraith(Replaces Reptiloids):Throws plasma projectiles that can behave different than Reptiloid projectiles.
  
• Crab Guard(Replaces Arachnoids):The Big Blue crusties with chainguns over their claws.

I actually really wanted to make crab enemies. Maybe will make later.

Originally posted by Thanadrax/Cream:

I actually really wanted to make crab enemies. Maybe will make later.

Okay.

What about some enemies from Aqua Teen Hunger Force:Zombie Ninja Pro-Am?

Here's what I think they would do in Serious Sam Fusion:
Carl's Crabs(Replaces Hoppers):They crawl towards you,and leap when close enough
Turkitrons(Replaces Kleers):They use laser socks to shoot at you!
Brownie Monsters(Replaces Harpies):Spits projectiles that go in arc
Living Trees(Replaces Gnaars):Giant,slow moving trees that hit you with their branches!
Wisdom Cubes(Replaces Flying Gnaars):Can teleport around you when damaging them!
Mooninites(Replaces Zorgs):Err's lasers are fast while Iritiknot's are slow but can deal heavy damage!
Lunar Tank(Replaces Reptiloids):A pizelated tank that shoots Giant pixel lasers at you!
M.C. Pee Pants(Replaces Arachnoid Generals):A giant spider who welds a hellfire rifle,and shoots fireballs at you!
Carl(Replaces Beheaded soldiers):Can shield himself with a Trash can,and use a club to attack!

Oh,how about hybrids!

• Beheaded Zorg Flamer(Beheaded Firecracker + Zorg Commander)(Replaces Zorg Commnaders):Shoot powerful firecracker shots in a spread!
  
• Zum'Kleer(Zum'bul + Kleer)(Replaces Zum'buls):They can switch from a Zum'bul style fightning stance to a Kleer style fighting stance!
  
• Fiendian Reptiloid Cacodemon(F.R. Demon + Cacodemon(Doom))(Replaces F.R. Demons):Flying variants of F.R. Demons that can also shoot Cacodemon projectiles!
  
• Beheaded Zombieman,Bomb-throwing Shotgunner(Beheaded Bomber + Shotgun Guy(Doom))(Replaces Beheaded Bombers):They hold a shotgun while they throw bombs!
  
• Kleer Vortigaunt(Kleer + Vortigaunt(Half-Life))(Replaces Kleer):Tries to struck you with lightning,and throws lightning chains!
  
• Black Kleer(Kleer+ Black Bony(The Binding of Isaac:Repentance)(Replaces Kleer):Lobs bombs and explodes upon death!

Pretty cool ideas! I like the hybrid one.

Originally posted by Thanadrax/Cream:

Pretty cool ideas! I like the hybrid one.

Thanks! ;3