SCP-106

This creature enters the battlefield under no
player's control (This creature has no controller).
Indestructible
At the beginning of each upkeep, untap this creature, then it attacks a creature that player
controls at random (Blockers may be declared).
Whenever SCP-106 deals combat damage to a creature, exile that creature, then return it to the battlefield under it's owner's control at the
beginning of the next end step with 3 -1/-1
counters on it.