Dark Sun Gwyndolin

When this card enters the battlefield,
summon X Black 1/1 Snake tokens with
Deathtouch, where X equals the amount of life
you have restored this turn.
{5}{w}{b}, {t}: Exile this card, then destroy all
creatures on the battlefield, restoring 1 life for
each Snake creature destroyed this way. Then
return this card to the battlefield tapped at the beginning of the next End Step.