Regenerating Hydra

Regenerating Hydra enters the battlefield with
3 +1/+1 counters.
At the beginning of each endstep, if
Regenerating Hydra has less than 3 +1/+1
counters on it, put a +1/+1 counter on
Regenerating Hydra.
Remove 3 +1/+1 counters from Regenerating
Hydra: Regenerate Regenerating Hydra.