It of the Horrid Swarm is a common Creature — Eldrazi Insect card from Eldritch Moon (EMN), collector number 8. Current market price: $0.11 (foil $0.48), TCGplayer market prices via Scryfall.
Emerge {6}{G} (You may cast this spell by sacrificing a creature and paying the emerge cost reduced by that creature's mana value.) When you cast this spell, create two 1/1 green Insect creature tokens.