Reaver Mantis

Hatch {u}{b}{g}
Flying
Sacrifice a creature: Reaver Mantis gets +1/+1
until end turn.
Sacrifice 2 Insects: Reaver Mantis gets +3/+3
until end turn and put a trample, menace, or deathtouch counter on Reaver Mantis.
If you paid Reaver Mantis's Hatch cost, then as it enters the battlefield it fights target creatures
you don't control.