Jei (comics)

Jei is an undying anthropomorphic wolf who appears in Usagi Yojimbo. He is often considered Usagi's true arch-nemesis. Jei believes that he is the "blade of the gods" - a samurai tasked by the deities to smite sinners. The problem is, any "sin" no matter how small, qualifies in Jei's mind. This has brought him to clash with Usagi many times.

Jei is able to resurrect and possess other bodies, making him essentially immortal.

In TMNT comics
Jei is a central villain in the IDW crossover comic, Namazu.