Sealock Monster
Creature — Octopus
Sealock Monster can't attack unless defending player controls an Island.
: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When Sealock Monster becomes monstrous, target land becomes an Island in addition to its other types.
Illustrated by
Theros#62UncommonEnglishLegality
Rulings
The effect making the land an Island doesn’t have a duration and will last indefinitely. The land retains any land types and abilities it already had. An Island has the ability “
: Add .”
Once a creature becomes monstrous, it can’t become monstrous again. If the creature is already monstrous when the monstrosity ability resolves, nothing happens.
Monstrous isn’t an ability that a creature has. It’s just something true about that creature. If the creature stops being a creature or loses its abilities, it will continue to be monstrous.
An ability that triggers when a creature becomes monstrous won’t trigger if that creature isn’t on the battlefield when its monstrosity ability resolves.