Master Splinter

Master Splinter (マスタースプリンター Masutāsupurintā) is a mutant rat who is the teacher, martial arts instructor, and foster father of the Ninja Turtles.

Iago PUC

 * Master Splinter appears in Comic Con Incorporated. A manager in the titular fictional hotel, he works as the yoga teacher.
 * Master Splinter is a guest crossover character in Marvel's Spider-Man: Webbed Champion, with Eric Bauza reprising his role from Rise of the Teenage Mutant Ninja Turtles. He appears alongside the Ninja Turtles in the episode "Legendary Universes, Part 5: Of Turtles and Spiders". While Leonardo and his brothers go with Spider-Man and his team battle Spider-Emperor's clan, he stays to help Mantis (who was created with a sample of the Mutagen Ooze) further understand her true inner nature.

Joint ideas
TBD...