Grakmaw, Skyclave Ravager

Grakmaw, Skyclave Ravager enters with three +1/+1 counters on it.
Whenever another creature you control dies, if
it had a +1/+1 counter on it, put a +1/+1
counter on Grakmaw.
When Grakmaw dies, create an X/X black
and green Hydra creature token, where X is
the number of +1/+1 counters on Grakmaw.