Leviathan enters the battlefield tapped and doesn't untap during your untap step.
At the beginning of your upkeep, you may sacrifice two Islands. If you do, untap Leviathan.
Leviathan can't attack unless you sacrifice two Islands. (This cost is paid as attackers are declared.)
Queen Creek Near Mint - $0.50
Queen Creek Lightly Played - $0.47
Queen Creek Moderately Played - $0.42
Queen Creek Heavily Played - $0.38
Queen Creek Damaged - $0.35
Tempe Near Mint - $0.50
Tempe Lightly Played - $0.47
Tempe Moderately Played - $0.42
Tempe Heavily Played - $0.38
Tempe Damaged - $0.35