Elder Deep-Fiend is a rare Creature — Eldrazi Octopus card from Modern Horizons 3 Commander (M3C), collector number 154. Current market price: $0.30, TCGplayer market prices via Scryfall.
Flash Emerge {5}{U}{U} (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, tap up to four target permanents.