Oshumare, Ocean's Judge

Trample
Oshumare, Judge of the Deep can only attack if defending player control an Island.
Whenever a Merfolk you control deals combat damage to a player, put a +1/+1 counter on it, and a Tide counter on that player. As long as a player has 5 or more Tide counters, Oshumare, Judge of the Deep can attack as if they controlled an Island.