Sleeping Potion is a common Enchantment — Aura card from Planeshift (PLS), collector number 34. Current market price: $0.19 (foil $0.66), TCGplayer market prices via Scryfall.
Enchant creature When this Aura enters, 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 this Aura.