Yogsothoth

Flying, Haste, Deathtouch, Menace, Triplestrike, Hexproof.
{x}{b}{b}, this creature gets +x/+x
{x}{b}Monstrosity x (if this creature isn't monstrous, put x +1/+1 counters on it and it becomes monstrous)
When this creature becomes monstrous, gain life equal to this creatures power.