From Teenage Mutant Ninja Turtles wiki
Splinter
Splinter is a mutated rat and the wise ninjutsu master who serves as the adoptive father and mentor to the Teenage Mutant Ninja Turtles.
Splinter, originally known as Hamato Yoshi in many iterations of the franchise, is a master of the martial arts who underwent a mutation after coming into contact with radioactive ooze. Following his transformation into an anthropomorphic rat, he took up residence in the sewers of New York City where he discovered four baby turtles similarly affected by the substance. He raised the brothers—Leonardo, Donatello, Michelangelo, and Raphael—as his own children, teaching them the ways of ninjutsu to protect themselves and others.
Role and Significance
As the mentor to the team, Splinter provides the discipline and spiritual guidance necessary for the turtles to combat the forces of the Shredder and other threats like Krang. He is a central figure in the lives of his students, often acting as a bridge between their lives as vigilantes and their identity as a family. His teachings are frequently supported by allies such as April O'Neil, who respects his wisdom and role in training the brothers to become heroes.
