Well...if I had my comics in front of me I could get the proper spelling of the name Stan Sakai gives a version of Splinter from his Usagi Yojimbo universe. I think it's Kakare, but I'm not getting any hits on Google, so that can't be right.

I've millicanon'd it that this name is the one that Yoshi gave Splinter when he was small. And while it translates to shard in English, the boys found Splinter easier to say.