Cocoon | Magic: The Gathering
Formats Cocoon is Legal in
Official Oracle Text for Cocoon
Enchanted creature doesn't untap during your untap step if Cocoon has a pupa counter on it.
When Cocoon enters the battlefield, tap enchanted creature and put three pupa counters on Cocoon.
At the beginning of your upkeep, remove a pupa counter from Cocoon. If you can't, sacrifice it, put a +1/+1 counter on enchanted creature, and that creature gains flying. (This effect lasts indefinitely.)
Official Rulings for Cocoon
10/4/2004 : Cocoon can be used on a tapped creature.
8/1/2005 : If the Aura is moved to a different creature, the number of counters is unchanged.