Viper

Flying
{t}: Sacrifice a Zerg Creature: Add mana of any
color equal to the sacrificed creature's toughness
+1, you don't lose this mana at the end of steps
and phases.
{r}{4}: Each Creature under your control deals
damage equal to it's power to target creature.
{2}: Target Creature loses it's attack power until
the beginning of your next Turn