Eater of Elders

Flying, Protection from Dragons
At the beginning of your upkeep, if
Eater of Elders has less than four +1/+1
counters on it, put a +1/+1 counter on it.
When Eater of Elders attacks, if it has four
or more +1/+1 counters on it, remove all
of them, and deal that much damage to
each untapped creature defending player controls.
Remove a +1/+1 counter: Regenerate.