Yorion, Sky Nomad is a rare Legendary Creature — Bird Serpent card from Ikoria: Lair of Behemoths Promos (PIKO), collector number 232p. Current market price: $1.85 (foil $1.89), TCGplayer market prices via Scryfall.
Companion — Your starting deck contains at least twenty cards more than the minimum deck size. (If this card is your chosen companion, you may put it into your hand from outside the game for {3} as a sorcery.) Flying When Yorion enters, exile any number of other nonland permanents you own and control. Return those cards to the battlefield at the beginning of the next end step.