Irma, Part-Time Mutant is a rare Legendary Creature — Human Mutant Shapeshifter card from Teenage Mutant Ninja Turtles Eternal (TMC), collector number 12. Current market price: $4.09 (foil $12.69), TCGplayer market prices via Scryfall.
At the beginning of combat on your turn, Irma becomes a copy of up to one other target creature you control, except her name is Irma, Part-Time Mutant and she has this ability. Then put a +1/+1 counter on her.