Spectral Prison is a common Enchantment — Aura card from Avacyn Restored (AVR), collector number 75. Current market price: $0.04 (foil $0.26), TCGplayer market prices via Scryfall.
Enchant creature Enchanted creature doesn't untap during its controller's untap step. When enchanted creature becomes the target of a spell, sacrifice this Aura.