Summoner's Egg is a rare Artifact Creature — Egg card from Fifth Dawn (5DN), collector number 157. Current market price: $3.87 (foil $9.95), TCGplayer market prices via Scryfall.
Imprint — When this creature enters, you may exile a card from your hand face down. When this creature dies, turn the exiled card face up. If it's a creature card, put it onto the battlefield under your control.