Swarm of Bloodflies is a uncommon Creature — Insect card from Khans of Tarkir (KTK), collector number 92. Current market price: $0.21 (foil $0.54), TCGplayer market prices via Scryfall.
Flying This creature enters with two +1/+1 counters on it. Whenever another creature dies, put a +1/+1 counter on this creature.