Glimmerdust Nap

Oracle Text

Enchant tapped creature

Enchanted creature doesn't untap during its controller's untap step.

Card Rulings

10/1/2007 Glimmerdust Nap can target only a tapped creature.
10/1/2007 If the targeted creature has become untapped by the time Glimmerdust Nap would resolve, Glimmerdust Nap doesn’t resolve for having an illegal target.
10/1/2007 If the enchanted creature becomes untapped, Glimmerdust Nap is put into its owner’s graveyard as a state-based action.