King Rat

King Rat is a large mutated rat humanoid. He was once a normal rat but radioactive goo spilled into the sewers where he lived, which turned him into an Alpha Rat (strongest rat of the pack). He then made all the other rats listen to him, and was more humanoid. King Rat lives in the sewers of Supreme City.

Wrath of Taze
When Jericho, Arkonai, Daniel Drake, Luke Oersted, American Booty, Auron Jet, Gaven, Riku, Karasu Kasei, and Zion X were in the sewers of Supreme City, they got jumped by King Rat (who was on a four wheeler) and his mutant rat pack. They had been in the sewers to escape from Taze. Everyone fought King Rat and his minions, quickly desposing of his mutant rats. King Rat was burned with acid by Ark, then ran into a bunch of trash cans, fell into a hole, and was knocked out. After going on a retarded rampage, his current whereabouts are unknown.

Trivia

 * King Rat was created by Imperial Wyrm to be a comic relief villain.