Glissa, the Traitor is a mythic Legendary Creature — Phyrexian Zombie Elf card from Mirrodin Besieged (MBS), collector number 96. Current market price: $3.71 (foil $10.49), TCGplayer market prices via Scryfall.
First strike, deathtouch Whenever a creature an opponent controls dies, you may return target artifact card from your graveyard to your hand.