Rain the Devourer

Riot, Menace.
{2}{b}{r}; Monstrosity 3. (If this permanent isn't monstrous, put 3 +1/+1 counters on it and it becomes monstrous.)
Enrage- When this creature takes damage, add
a number of +1/+1 counters equal to the damage
taken. If this creature is monstrous, double that
number.
{t},{b/g}; Sacrifice a creature. Gain life equal to that
creature's toughness.