IT

Cannot be blocked non-artifact creatures
Wither, First strike
IT gets +1/+1 for each creature with a
-1/-1 counter on it, and -1/-1 for each
creature with a +1/+1 counter on it.
{b}{t}: put a -1/-1 counter on target creature.
"I'm every nightmare you've ever had. I'm your worst dream come true."
-IT, in the guise of Pennywise