Triassic Egg is a rare Artifact card from Chronicles (CHR), collector number 110. Current market price: $0.42, TCGplayer market prices via Scryfall.
{3}, {T}: Put a hatchling counter on this artifact. Sacrifice this artifact: Choose one. Activate only if there are two or more hatchling counters on this artifact. • You may put a creature card from your hand onto the battlefield. • Return target creature card from your graveyard to the battlefield.