Massacre Wurm is a mythic Creature — Phyrexian Wurm card from Core Set 2021 (M21), collector number 114. Current market price: $4.77 (foil $11.75), TCGplayer market prices via Scryfall.
When this creature enters, creatures your opponents control get -2/-2 until end of turn. Whenever a creature an opponent controls dies, that player loses 2 life.