Kindred Summons is a rare Instant card from Lorwyn Eclipsed Commander (ECC), collector number 112. Current market price: $0.79, TCGplayer market prices via Scryfall.
Choose a creature type. Reveal cards from the top of your library until you reveal X creature cards of the chosen type, where X is the number of creatures you control of that type. Put those cards onto the battlefield, then shuffle the rest of the revealed cards into your library.