8. Piggsy (Manhunt)
As if Manhunt wasn't demented enough, Rockstar decided to throw in a clinically insane man who thinks he is a pig, to the extent that he wears a pig mask, and spends the entirety of the game running around, snorting, looking absolutely repellent, and most distressingly, trying to kill the player. Worse still, Piggsy is a bit of a pain to kill; he takes a lot of damage to knock off his feet, and is fiendishly skilled at tracking the player down, such that you'll need to be smart to evade him. The key to ending him is removing his favoured weapon - the chainsaw he refuses to let go of - but it will do little to quell the nightmares of the man-pig you're sure to have after playing this game.