Joker, Clown Prince of Crime

Annihilator 2 (Every time this creature attacks, defending player sacrifices two permanents.)

Devour 2 (As this creature enters the battlefield, you may sacrifice any number of creatures. It enters with a +1/+1 counter on it for each creature sacrificed this way.)

Whenever a player sacrifices a permanent, put a +1/+1 counter on this creature