Community

Harbor Serpent
Creature — Serpent
Islandwalk (This creature can't be blocked as long as defending player controls an Island.)
This creature can't attack unless there are five or more Islands on the battlefield.
Like most giant monsters villagers worship as gods, it proves a fickle master.
Rulings (2)
Harbor Serpent's abilities care about lands with the land type Island, not necessarily lands named Island.
Aug 15, 2010
The second ability checks how many Islands are on the battlefield (regardless of who controls them) only as attackers are declared. Once Harbor Serpent is declared as an attacker, it will continue to attack even if the number of Islands on the battlefield falls below five.
Aug 15, 2010
Legality
Formats by platform
Commander
Competitive
Community & retro
Printings (3)
M13#53$0.12
Magic 2013
M12#56$0.16
Magic 2012