Rova, Wisdom of the Pack

Indestructible
Graft 6 (This creature enters the battlefield with
six +1/+1 counters on it. Whenever another
creature enters the battlefield, you may move a
+1/+1 counter from this creature onto it.)
Whenever you move any number of +1/+1
counters from one creature to another, put a
+1/+1 counter on target creature.