Thassa, Deep-Dwelling is a mythic Legendary Enchantment Creature — God card from Secret Lair Drop (SLD), collector number 1279. Current market price: $37.29 (foil $40.18), TCGplayer market prices via Scryfall.
Indestructible As long as your devotion to blue is less than five, Thassa isn't a creature. At the beginning of your end step, exile up to one other target creature you control, then return that card to the battlefield under your control. {3}{U}: Tap another target creature.