The Mimeoplasm is a rare Legendary Creature — Ooze card from Outlaws of Thunder Junction Commander (OTC), collector number 234. Current market price: $0.30, TCGplayer market prices via Scryfall.
As The Mimeoplasm enters, you may exile two creature cards from graveyards. If you do, it enters as a copy of one of those cards with a number of additional +1/+1 counters on it equal to the power of the other card.