Dolphin

The Dolphin is found in Atlantica in Kingdom Hearts and Kingdom Hearts Final Mix. The only character in the game to tell you about the Dolphin is Flounder. The interesting thing is that Flounder identifies the Dolphin as a 'Giant fish.' It gives Sora and his party a ride past the currents that block the passage to the Shipwreck. The Dolphin will not be available if there any Heartless currently in the Undersea Gorge, so one must defeat them all before being able to advance the story, and reach the Shipwreck.