Captain Marvel is not a character from 'The Marvelous Misadventures of Flapjack', which is an animated television series created by Thurop Van Orman. Instead, Captain Marvel is a superhero from the Marvel Comics universe. If you are referring to Captain K'nuckles, a character from the series, he is an eccentric and boastful pirate who claims to be a captain. He serves as a mentor and father figure to Flapjack, leading him on various adventures in pursuit of the mythical Candied Island. Captain K'nuckles is known for his wooden body parts and his exaggerated tales of adventure.