Rat King (Teenage Mutant Ninja Turtles) cameo appearance in "Teenage Mutant Ninjas Turtles" Vol. 4, watching as Splinter succumbs to a heart attack and dies while retrieving milk from a refrigerator. Much of the Rat King's origin is later revealed in an issue of "Tales of the Teenage Mutant Ninja Turtles" Vol. 2; the story reveals that a group of beings known as the Pantheon exists, with each member of the group having jurisdiction over a species of animal. When the time of the Pantheon member who rules the rats reaches an end, a new one is chosen, a scarred and heavily bandaged (explaining the Rat
Rat King (Teenage Mutant Ninja Turtles) to fight off any alien threats and was given a test run against the Turtles, who broke into Bishop's laboratory looking for the kidnapped Splinter. The Slayer was presumed destroyed when a fight between him, the Turtles, Splinter and Bishop flooded the agent's lab. In actuality, the Slayer survived and was sent hurdling through the sewers, eventually being deposited near the industrial park the events of "I, Monster" take place in. Losing several of his robotic parts, cloaking device and healing ability, the Slayer degenerated into an even more monstrous form, becoming the Rat King. The Rat King makes a