Splinter, the Mentor (Teenage Mutant Ninja Turtles Eternal #3)

Legendary Creature — Mutant Ninja Rat - {1}{B}
Menace
Whenever Splinter or another nontoken creature you control leaves the battlefield, create a Mutagen token.
Partner—Character select (You can have two commanders if both have this ability.)
2/2
„"We choose what holds us back."“