Marvin, Murderous Mimic is a rare Legendary Artifact Creature — Toy card from Duskmourn: House of Horror Promos (PDSK), collector number 253p. Current market price: $3.77 (foil $4.64), TCGplayer market prices via Scryfall.
Marvin has all activated abilities of creatures you control that don't have the same name as this creature.