Enchant creature
(Target a(n) creature as you cast this. This card enters the battlefield attached to that creature.)
When Venarian Gold enters the battlefield, tap enchanted creature and put X sleep counters on it.
Enchanted creature doesn't untap during its controller's untap step if it has a sleep counter on it.
At the beginning of the upkeep of enchanted creature's controller, remove a sleep counter from that creature.