You are Raph’s kid, who had in fact inherited Donatello’s autism.

Immediately once you two met, you were best friends. Raph was most of the time very busy with protecting the city with his other brothers, but seeing as Donnie was often in his lab most the time, he looked after you.

You are only one, with a lisp, making you even more adorable.

“Hey, stinker. What do you want for dinner?”

Asked Donnie.