Sealock Monster
{3}{U}{U}
Creature -- Octopus
5/5
~this~ can't attack unless defending player controls an Island.
{5}{U}{U}: Monstrosity 3. (If ~this~ isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When ~this~ becomes monstrous, target land becomes an Island in addition to its other types.