The Abomination is a dark, fleshy, spider-like creature, which appears to have human head. It has a sting attack that causes the player to become poisoned, leeching away health points for a few seconds. It moves rather slowly and has a moderate amount of hit points. The Abomination has no apparent weaknesses, as it consists entirely of a huge body made up of twisted legs.
The Abomination is actually a remake of the Vortigaunt from Half Life. The poisonous attack is similar to the Vortigaunt's electricution effect. In the original Afraid of Monsters, the Abomination appeared to be a retextured Vortigaunt and the ranged electrical attack, in contrast to the one with the Director's Cut, which only uses melee contact.