Riptide Shapeshifter is a uncommon Creature — Shapeshifter card from Onslaught (ONS), collector number 109. Current market price: $0.25 (foil $3.89), TCGplayer market prices via Scryfall.
{2}{U}{U}, Sacrifice this creature: Choose a creature type. Reveal cards from the top of your library until you reveal a creature card of that type. Put that card onto the battlefield and shuffle the rest into your library.