Sphinx's Herald is a uncommon Artifact Creature — Vedalken Wizard card from Shards of Alara (ALA), collector number 58. Current market price: $0.18 (foil $0.45), TCGplayer market prices via Scryfall.
{2}{U}, {T}, Sacrifice a white creature, a blue creature, and a black creature: Search your library for a card named Sphinx Sovereign, put it onto the battlefield, then shuffle.