Meandering Towershell is a rare Creature — Turtle card from Secret Lair Drop (SLD), collector number 236. Current market price: $1.12 (foil $0.63), TCGplayer market prices via Scryfall.
Islandwalk (This creature can't be blocked as long as defending player controls an Island.) Whenever this creature attacks, exile it. Return it to the battlefield under your control tapped and attacking at the beginning of the declare attackers step on your next turn.