Coastline Devourer

Ward {4} {u}{u}, {t}: Return Coastline Devourer
to your hand.
When Coastline Devourer enters the battlefield
or attacks, create a 1/1 blue
crustacean creature token with menace.
Coastline Devourer can not attack an opponent
who does not control an island.
If a crustacean creature deals combat damage to
an opponent, you may sacrifice it. Make a land
that player controls an island, in addition
to its other types.