Tommaso Hamoto in Teenage Mutant Ninja Turtles the Bayverse(2014-2016).
In every universe, Tommy, a human boy, is always found in the trash or in the sewers by Master Splinter and raised alongside his four turtle mutant brothers, trained by their father Splinter as Ninjas.
In this universe, while scavenging for food for himself and his sons during the winter time, Splinter ends up finding an abandoned baby boy and ends up taking him home to help warm him before the cold could kill him. While Splinter was trying to figure out a way to safely leave the child so that a human could save him, he noticed that the baby and his four sons instantly bonded with one another. After a few days, the thought of separating the child from his sons and himself started to pain him, but what's more is that this child reminded him so much of the little girl that saved him and his son's life, April O'Neil. Then Splinter finally came to the decision that he would raise this child alongside his sons and gave him the name Tommaso.