Enchant creature you control
Enchanted creature gets +3/+3.
At the beginning of your upkeep, sacrifice a creature.
6/15/2010 When Demonic Appetite’s triggered ability resolves, you may sacrifice the creature enchanted by Demonic Appetite. If you control no other creatures, you’ll have to sacrifice that one.
6/15/2010 If another player gains control of either Demonic Appetite or the enchanted creature (but not both), Demonic Appetite will be enchanting an illegal permanent. The Aura will be put into its owner’s graveyard as a state-based action.