The Mask of the Sleeper

Mask of the Sleeper enters the battlefield with
five slumber counters on it.
If there are no slumber counters on Mask of the Sleeper, sacrifice it and equipt creature:
Create a 12/12 Black legendary Sleeper Demon creature token with trample and indestructible.
Whenever equipt creature deals combat damage
to a opponent, remove a slumber counter from
Mask of the Sleeper.