Necgrogen Behemoth

Menace, Trample, Grasp 1 (When this creature dies, you may pay {1} and discard a card. If you do, return it to its owner's hand. X cannot be zero)
Necrogren Behemoth enters the battlefield with X +1/+1 counters on it.
When Necrogren Behemoth dies, put a -1/-1 counter on each of up to X target creatures, where X is Necrogen Behemoth's power.