Entropic Eidolon is a common Creature — Spirit card from Dissension (DIS), collector number 45. Current market price: $0.14 (foil $0.30), TCGplayer market prices via Scryfall.
{B}, Sacrifice this creature: Target player loses 1 life and you gain 1 life. Whenever you cast a multicolored spell, you may return this card from your graveyard to your hand.