Lobotomy

The Lobotomy is a monster appearing in Silent Hill: Revelation. It is seen briefly within Brookhaven Asylum.

Appearance
Lobotomy is very humanoid in nature, resembling an emaciated man with an absent face, with the only feature being a huge, grotesque hole through which it emits inhuman, throaty "roaring" noises, along with an exposed brain. It may have been influenced by beasts such as the Prisoner Minion and Lurker.

Silent Hill: Revelation
As Heather Mason ventures deeper into Brookhaven Asylum in search for Leonard Wolf, Lobotomy emerges from the shadows and almost succeeds in forcibly subduing Heather, but Heather manages to draw her handgun and fire a bullet into Lobotomy's head fissure, instantly killing the monster.

Given Leonard's surgical scars on the back of his head and claiming he is simply an "ongoing project", it is entirely possible that Lobotomy could have once been a completely normal human that Claudia Wolf and the Order of Valtiel had been physically experimenting on. This is also supported by Lobotomy's basic figure being very humanoid.

Symbolism
The Lobotomy's name is a reference to a now-archaic surgical procedure called a lobotomy, which was once thought to reduce mental illness by literally scraping away brain tissue.

The Lobotomy could represent one of the asylum patients being physically experimented, or a victim of mental illness.

It could also represent Heather's fears of becoming mentally ill. Earlier, she said, "It's just one more thing to prove I'm going crazy!"