Mimeoplasm, Revered One is a mythic Legendary Creature — Ooze card from Aetherdrift Promos (PDFT), collector number 214p. Current market price: $0.97 (foil $2.98), TCGplayer market prices via Scryfall.
As Mimeoplasm enters, exile up to X creature cards from your graveyard. It enters with three +1/+1 counters on it for each creature card exiled this way. {2}: Mimeoplasm becomes a copy of target creature card exiled with it, except it's 0/0 and has this ability.