The Exterminator is inspired by the T-800, who comes from the Terminator franchise. The Exterminator is an artificially intelligent humanoid robot created by Skynet to destroy other life forms. The name "Exterminator" could be taken as a reference to the Daleks from Doctor Who, who say "Exterminate."
The Exterminator is a large humanoid machine that has armor plating covering most of it's exterior. It has large red glowing eyes and a bright red spot in the middle of it's chest, signifying a heart of some sort. He bears similar night-vision to the Predator, except with a red tint. (Tint may change with skins.)
The Exterminator's ability allows him to see players highlighted in red from a certain distance for a short time. Highlighted players can be seen through walls as long as they're within range. Activating the ability triggers the taunt sound the Exterminator made from the Old Beta.