Volrath, the Shapestealer is a mythic Legendary Creature — Phyrexian Shapeshifter card from Commander 2019 (C19), collector number 51. Current market price: — (foil $0.67), TCGplayer market prices via Scryfall.
At the beginning of combat on your turn, put a -1/-1 counter on up to one target creature. {1}: Until your next turn, Volrath becomes a copy of target creature with a counter on it, except it's 7/5 and it has this ability.