Glissa, the Traitor is a mythic Legendary Creature — Phyrexian Zombie Elf card from Magic Player Rewards 2011 (P11), collector number 96. Current market price: $10.00, 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.