Mikaeus, the Unhallowed — Commander Masters #1061

Intimidate (This creature can't be blocked except by artifact creatures and/or creatures that share a color with it.)

Whenever a Human deals damage to you, destroy it.

Other non-Human creatures you control get +1/+1 and have undying. (When a creature with undying dies, if it had no +1/+1 counters on it, return it to the battlefield under its owner's control with a +1/+1 counter on it.)