After several years of absence, the Rat King (in ghost form) reappears in a brief 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 King's appearance) patient at a hospital. Becoming the Rat King, the man challenges Splinter to a battle, which he loses after a long fight. With the Rat King defeated, Splinter is offered a chance to take his place in the Pantheon, which he refuses. Accepting Splinter's decision, the Pantheon and Rat King leave, though not before stating that Splinter will be offered membership in the Pantheon one more time, at the moment of his death.