Protean Hydra

Protean Hydra enters the battlefield with X
+1/+1 counters on it.
If damage would be dealt to Protean Hydra,
prevent that damage and remove that many
+1/+1 counters from it.
Whenever a +1/+1 counter is removed from
Protean Hydra, put two +1/+1 counters on it
at the beginning of the next end step.