Other creatures you control get +1/+1.
Enchant creature
Enchanted creature can't attack or block.
Enchanted creature has "At the beginning of your upkeep, you lose 1 life."
Whenever enchanted creature deals damage to a player, return target creature that player controls to its owner's hand.
Tap all creatures target player controls. Those creatures don't untap during that player's next untap step.
When Sleeper Agent enters the battlefield, target opponent gains control of it.
At the beginning of your upkeep, Sleeper Agent deals 2 damage to you.
Enchanted creature has fear. (It can't be blocked except by artifact creatures and/or black creatures.)
When Sleeper's Guile is put into a graveyard from the battlefield, return Sleeper's Guile to its owner's hand.
Whenever enchanted creature deals combat damage to an opponent, you may draw a card.
When Sleeping Potion enters the battlefield, tap enchanted creature.
Enchanted creature doesn't untap during its controller's untap step.
When enchanted creature becomes the target of a spell or ability, sacrifice Sleeping Potion.