Avarin

Lifelink (Damage dealt by this creature also causes
you to gain that much life.)
At the beginning of your end step, if an opponent
lost life this turn, put a +1/+1 counter on Avarin
{1}{w/b} Regenerate Avarin (The next time this
creature would be destroyed this turn, it isn't. Instead
tap it, remove all damage from it, and remove it from
combat.)