Blood Speaker is a uncommon Creature — Ogre Shaman card from The List (PLST), collector number CHK-103. Current market price: $0.25, TCGplayer market prices via Scryfall.
At the beginning of your upkeep, you may sacrifice this creature. If you do, search your library for a Demon card, reveal that card, put it into your hand, then shuffle. Whenever a Demon you control enters, return this card from your graveyard to your hand.