The Undying

Undying (When this creature dies, 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.)
Unleash (You may have this creature enter the battlefield with a +1/+1 counter on it. It can't block
as long as it has a +1/+1 counter on it.
Remove all +1/+1 counters from this creature at
the beginning of each end step.