Ashen Nibelsnarf

When Ashen Nibelsnarf enters the battlefield,
you may sacrifice any number of small monsters.
Then, Ashen Nibelsnarf deals X damage to each
other creature, where X is the number of +1/+1
counters on it.
Whenever a small monster you control dies, put a
+1/+1 counter on Ashen Nibelsnarf.