In the 2012 cartoon, Splinter (voiced by Hoon Lee) is once again Hamato Yoshi, the son and heir of Hamato Clan jonin Hamato Yuta, whose clan had a historical rivalry with the Foot Clan until the Foot were defeated when Yoshi was 2 years old, and Oroku Saki (the Foot Clan's heir) was adopted into the Hamato family. Despite being raised as brothers, both Yoshi and Saki eventually became rivals due to the love of Tang Shen, whose decision to marry Yoshi drove Saki into learning of his true heritage and turn against his adoptive brother, killing Shen and adopting Karai, who was Yoshi and Shen's beloved baby daughter Miwa then, while leaving her birth father for dead. Traveling to New York City, Yoshi had just bought the Turtles from a pet store when he overheard a conversation in a nearby ally between two human-disguised Kraangdroids who attempted to kill him for spying on them. Yoshi fought back, eventually knocking a canister of mutagen out of their hands and getting covered with the mutagen inside when it smashed, and the Turtle's bowl with it. As the result of stepping on a brown rat while entering the alley, he mutated into a humanoid mutant brown rat while the Turtles mutated into their current mutant state.