Reaver Swarm

Haste, menace
Unleash (You may have this creature enter the battlefield with a +1/+1 counter on it. It can't block as long as it has a +1/+1 counter on it.)
Reavers are bread for one purpose, and they chant that purpose in the performance of their duties. "Hoh hegh! Hoh hegh! Hoh..."