This Idea is selfmade and not very overthought, so pls comment your ideas to the Characters.

History
The Entity has many Killers and they all do their best on their job, to hunt and kill. But the Entity wanted to know something more about the Survivors, more about their fears. It observed them all, to find something, something they all fear, something terrible enough, that it confuse them first, before rip them apart. And the Entity found something, all Survivors know fro their childhood, the Boogeyman.
The Problem was, to give him a shape, that could include the fear of all of them, but they all had other figures. So the Entity quit and let a shapeless form back, which should form itselfe. The shapeless thing formed itselfe into something strange, looking like a human but different. It growth in the length and created a black smoking and a tophat. The face was replaced by a white shapeless mask showing no emotion. It grabbed a staff and started to walk into the Entitys worlds, looking for grown up, to bring their inner kids out.

Into open arms
Every Kid fear it, to walk right into the danger. Tophat knows that and he will try to make this horror reality.
Tophat can every five(5) seconds, Teleport five(5) meters in front of the survivor, during the chase. He will remain one(1) second in a position, with his hands opened. If the Survivor walks into him, he will grab the Survivor and take him on his shoulder, ready to hook him.
If not he will just go back into the normal phase and can continue the chase.

Its real
When you grow up, you forget about your chidhood nightmares and just live your life. But when you come to this place, you meet horrors, that are real and not in your head. Everytime Tophat is chasing a Survivor, the Survivor gets a Stack. The Stacks will do following things:

1-3 Stacks
The Survivor will hear sometimes giggel and the the heartbeat starts at random, even if the Killer isnt around.
A 5% decreased action speed.

4 Stacks
Trees will form hands and it looks like they are trying to grab the Survivor
A 10% decreased action speed.

5 Stacks
The giggel appears more often and it looks like the Killer is peeking around corners, but when the Survivor look at him the Killer will dissappear.
A 15% decreased action speed.

Silent Helper
One Survivor gets marked. If the marked Survivor sees another one, the position of the Survivor will be showned to the Killer for 1/3/5 seconds. This Perk has a 200 seconds cooldown.

Beat Into
Your attacks have a 15/20/25% chance to confuse a Survivor. A confused Survivor will have switched controls (a => d, d=>a,s=>w, w =>s) for 1/3/5 seconds

Head

• Tophat = A Black Tophat and a white mask with two eyeholes.
  
• Bloody Tophat = Still a normal Tophat, but with a bloody mask.
  
• Melon = A different Hat, smaller then the Tophat, but also fashioned.
  
• Twisted Mind = A mask, with one half black and one white with a black Melon.

Body

• Smoking = Black Smoking with a white shirt and a red Fly.
  
• Bloody Smoking = A Black Smoking with a bloody shirt and a white Fly.
  
• Stripped Smoking = A Smoking with stripes
  
• Twisted Body = A white and black Smoking without a Fly

Weapon

• Staff = A normal and common Staff, nice to walk with it
  
• Bloody Staff = People got hit really hard by this Staff.
  
• Raven Staff = A Raven was placed on the Staff, to make it look more mystical, but to be honest, its really cool.
  
• Patrituism Staff = If you want to show these communism Survivor, how you beat em up in America, use this Staff with an Eagle on
  it.

Tophat picks the Survivor up, that he can eat him whole. It looks like he would inhale the Survivor without chewing.
Tophat knocks on the closet before opening and taking the survivor.

That was the Idea to the Killer Tophat/Boogeyman. If you have Ideas to him or the New Survivor ( I would make him like 12 years old), just comment it and I would think about It. Or you can ask me if you wanna do it yourselfe :)

Idea from: ShyGuy 99 aka. Techpriest, Ginus.