Corvil, Bio Mutation

Graft 3, Evolve
{g/u}{u/b}, Remove a +1/+1 counter from Corvil, Bio Mutation: Place a 1/1 Piranha Mutant Fish token onto the battlefield under your control.
Whenever an opponent draws a card (other than the first one for the turn) you may place a +1/+1 counter on Corvil, Bio Mutation.