Nirkana Assassin is a common Creature — Vampire Assassin Ally card from Battle for Zendikar (BFZ), collector number 118. Current market price: $0.06 (foil $0.27), TCGplayer market prices via Scryfall.
Whenever you gain life, this creature gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)