Lurker

Lurker is a mutant boss encountered in the chapter Among the shadows.

Appearance
He resembles a skeleton, except his body is black. Lurker is about 4.5m tall. His white eyes are glowing in the dark.

Behaviour
Lurker hides in the shadows, closing his eyes. Right before he attacks, he opens them and appears behind you. He preferes to be behind his prey. When he opens his eyes and we hear sound resembling creaky boards, we should turn around quickly dash away. Killing him is impossible due to his tought skin. Even explosions can't hurt him. The only way to do it is using the Dematerialization Field. Untill then we must escape from it. There are only a couple encounters with him throughout the level.