The Whale in Paper Mario. The Whale is a character in Paper Mario. His role is to serve as the main way to get to Lavalava Island from Toad Town, similar to how the Black Skull is the main way to get to Keelhaul Key (which is also the setting of the 5th chapter) in Paper Mario: The Thousand-Year Door. The Whale is constantly mistaken for a giant tuna by Kolorado. The Whale also appears in Mario Party 5 in the Undersea Dream gameboard.
After Mario has heard about the fifth Star Spirit, Misstar, being on Lavalava Island, he decides to go to the docks of Toad Town to find a boat. When Mario arrives in the area, he sees a Whale in the docks. Mario also meets Kolorado, who is trying to go to Lavalava Island. When Mario Ground Pounds the Whale or hits him with a hammer three times, he wakes up and starts complaining about a bellyache. He opens his mouth so Mario can check for any problems in its belly. The Whale's belly is devoid of light and filled with some water, some crates, and bottles the Whale accidentally ate. Mario uses Watt to brighten his surroundings, and he sees Fuzzipede bouncing off of the belly's lining. The two engage in combat, and the Whale then ejects them from his body via his blowhole.
After Mario defeats Fuzzipede, the Whale feels better and suggests that Mario should become a doctor, and even calls him "Dr. Mario". The Whale apologizes to Fuzzipede and mentions that he was taking a nap with his mouth open. Fuzzipede forgives the Whale and thanks Mario as he bounces away. In return for the assistance, the Whale transports Mario back and forth from Toad Town to Lavalava Island when needed.