In the 2012 Teenage Mutant Ninja Turtles series, Splinter originally had the human name Hamato Yoshi.
Before becoming a mutant rat, Yoshi was a skilled martial artist and the father of Miwa. The series presents his rivalry with Oroku Saki, who later becomes the Shredder, as a major part of Splinter’s backstory. Yoshi’s transformation occurs after exposure to mutagen, while the turtles undergo their own mutation.
The name Hamato Yoshi is used in several versions of the franchise, but the details of his history differ between adaptations. In some continuities, he begins as a human martial artist; in others, Splinter’s origins are reimagined.
Viewers sometimes confuse Yoshi with Oroku Saki because both are central figures in the backstory. They are rivals, not alternate names for the same character.