Dolphin

The dolphin is found in Atlantica in  and Kingdom Hearts II. The dolphin in the Undersea Valley is available even if there are Heartless, but Sora is unable to ride the dolphin until the Heartless are defeated.

Kingdom Hearts
During Sora, Donald, and Goofy's first visit to Atlantica, the dolphin swims around in several places. Flounder calls it a "giant fish". It helps the party to reach the Sunken Ship, particularly when Sora does not yet have access to the Mermaid Kick ability. It also leads Sora to other places in Atlantica if he lets go of the Dolphin before reaching the Sunken Ship.

Kingdom Hearts II
In Sora, Donald, and Goofy's second visit to Atlantica, dolphins like the one who helped Sora a year ago participate in the first song, "Swim This Way". Later, several dolphins dance along to "Under the Sea" along with Sebastian and Ariel, and more dolphins take part in the performance of the final song, "A New Day is Dawning".

Appearance
The dolphin is a medium-sized, cetacean mammal with a dark grey body. It has two oval shaped eyes and closely resembles the features of a. The dolphin has two flippers, a long dorsal fin, a blow hole, and a horizontal fluke split into two by a notch in the middle. The horizontal tail separates this dolphin from real in that instead of having horizontal tail fins, this dolphin's tail fins are vertical.

Origin
The dolphin first appeared in the 1989 Disney film, . The dolphin appears twice in the film with both features being a minor supporting role. The first appearance is during the song "Under the Sea". Shortly into the song, the dolphin is shown swimming around, content and happy with its life in the sea. The dolphin is last shown at Prince Eric and Vanessa's wedding, where it successfully interrupts the false wedding alongside other sea creatures.