Metal-Shelled Stalker

Skulk (This creature can't be blocked by creatures with greater power)
Whenever Metal-Shelled Stalker deals damage to a planeswalker, destroy that planeswalker.
{t}: Metal-Shelled Stalker deals 2 damage to target player.
"Unable to make peace with Morodin, the golems were forced to send small but deadly assassins to defend themselves."