Melkor, Emperor of Gromgar

Undying (When this permanent is put into a graveyard from the battlefield, if it had no +1/+1 counters on it, return it to the battlefield under its owner’s control with a +1/+1 counter on it.”)
Whenever a +1/+1 counter is put on a creature create a 1/1 imp creature token.
{2}{b}{b}: Put a +1/+1 Counter on target creature