Cast Panini (Chowder) as Ariel Flapjack (The Marvalous Misadventures of Flapjack) as Eric Lowly (from The Busy World of Richard Scarry) as Flounder Captain Knuckles (The Marvalous Misadventures of Flapjack) as Sebastian Father Cat (from The Busy World of Richard Scarry) as King Triton Endvie (Chowder) as Ursula Ariel's Sister played by The Girls (The Marvalous Misadventures of Flapjack) Sally Syrup (The Marvalous Misadventures of Flapjack) as Vanessa