Leviathan
{5}{U}{U}{U}{U}
Creature -- Leviathan
10/10
Trample
~this~ enters tapped and doesn't untap during your untap step.
At the beginning of your upkeep, you may sacrifice two Islands. If you do, untap ~this~.
~this~ can't attack unless you sacrifice two Islands. (This cost is paid as attackers are declared.)