Eldrazi Mimic is a rare Creature — Eldrazi card from Oath of the Gatewatch (OGW), collector number 2. Current market price: $1.02 (foil $2.75), TCGplayer market prices via Scryfall.
Whenever another colorless creature you control enters, you may have this creature's base power and toughness become equal to that creature's power and toughness until end of turn.