Flying Swarm of Bloodflies enters the battlefield with two +1/+1 counters on it. Whenever another creature dies, put a +1/+1 counter on Swarm of Bloodflies.
Despite the name, they'll happily devour the flesh too.
Near Mint - $200
Lightly Played - $200
Moderately Played - $100
Heavily Played - $100
Damaged - $100
Near Mint Spanish - $200
Lightly Played Spanish - $200
Moderately Played Spanish - $100
Heavily Played Spanish - $100
Damaged Spanish - $100