Sea monster

The sea monster is a giant marine reptile fought as a miniboss in Zelda's Adventure. It is among the largest creatures in the game, even when only factoring in the visible portion of its body. It appears the first time Zelda uses the raft to cross the Great South Sea to the Sea Island, at which point it interrupts her trip halfway through. To attack, it gradually rises out of the water while swimming around the raft. After several hits, it explodes with the same effect as defeated shrine bosses.

In-game, the sea monster never fully extends from the water while facing south, though unused sprites exist for it doing so.