As long as your devotion to blue is less than five, Thassa isn't a creature. (Each U in the mana costs of permanents you control counts toward your devotion to blue.)
At the beginning of your upkeep, scry 1.
1U: Target creature you control can't be blocked this turn.
Near Mint - $500
Lightly Played - $400
Moderately Played - $400
Heavily Played - $300
Damaged - $300
Near Mint Spanish - $500
Lightly Played Spanish - $400
Moderately Played Spanish - $400
Heavily Played Spanish - $300
Damaged Spanish - $300