Easy 10 points question about F.E.A.R 2?

Can anyone tell me who these enemies are from the fear 2 game. They look lke a fat man with a brown leather jacket on. They always are quiet n when u disturb them they scream in you face which causes ur vision to go all yellowish. Also they ressurect dead bodies. What are these enemies. What site can I go to, to get more info on them. Also I noticed that u cant kill them so how can I kill them. Thanks and 10 points to best answer