Protean Hydra (M11) from Magic 2011, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: Jim Murray
• Card Text:
  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.