Sand Squid is a rare Creature — Squid Beast card from Mercadian Masques (MMQ), collector number 96. Current market price: $0.59 (foil $8.49), TCGplayer market prices via Scryfall.
Islandwalk (This creature can't be blocked as long as defending player controls an Island.) You may choose not to untap this creature during your untap step. {T}: Tap target creature. That creature doesn't untap during its controller's untap step for as long as this creature remains tapped.