The Sibsig Ceremony is a rare Legendary Enchantment card from Tarkir: Dragonstorm (TDM), collector number 91. Current market price: $0.37 (foil $0.41), TCGplayer market prices via Scryfall.
Creature spells you cast cost {2} less to cast. Whenever a creature you control enters, if you cast it, destroy that creature, then create a 2/2 black Zombie Druid creature token.