Cuphead is a young man with a teacup for a head. According to the creators, Chad and Jared Moldenhauer, the design was inspired by a 1936 Japanese propaganda cartoon that featured a character who also had a teacup for a head. Much like the rest of the Cuphead game itself, the character is meant to pay homage to the rubber hose designs of classic cartoon characters from the Golden Age of American animation, namely Mickey Mouse, Bugs Bunny, and Felix the Cat. According to the Moldenhauers, Cuphead initially went through over 150 redesigns, some of which didn't have the teacup head.
Cuphead lives in the Inkwell Isles with his brother Mugman under the watchful eye of their elderly caretaker, the Elder Kettle. One day, against the Elder's wishes, the boys wander far from home and end up at the Devil's Casino, where they begin to play craps. The game earns them a winning streak, which catches the attention of the Devil himself. Impressed, he strikes a deal with the brothers to raise the stakes of the game; if Cuphead and Mugman can win one more roll, all the money in the casino is theirs; if not, the Devil will take their souls. Overcome with greed, Cuphead ignores his brother's pleads and plays one more round, only to lose when he rolls snake eyes. When they plead for mercy, the Devil offers another deal; if he can collect the "soul contracts" of previous debtors by midnight the next day, he might spare them. To aid them, the Elder Kettle gives them a potion that gives them the ability to fire energy blasts from their fingers. With their new powers, the boys set off on their journey across the Isles, though not before the Elder Kettle warns them of the dangers ahead.
In the game, the debtors are the various difficult bosses that the brothers must defeat at the end of each level, while at the same time trying to avoid many of the Devil's goons. Once Cuphead and Mugman have successfully collected all of the contracts, they return to the Casino but find themselves blocked by the manager, King Dice. He directly challenges the boys after claiming that their victories have made him lose a bet against the Devil. After defeating King Dice, the boys confront the Devil, in which the player is given the choice whether to turn over the contracts to him or not; if the player decides to do so, he will turn Cuphead and Mugman into demonic creatures. If the player refuses, it will enrage the Devil, allowing the final battle to ensue. Eventually, the brothers prevail against him and burn the contracts; in return, the debtors, now free from their fear of the Devil, celebrate the duo's heroic actions.
A costume for the Mii Gunner modeled after Cuphead was made available as a part of the Round 5 batch of DLC costumes. Much like in the original game, the costume's "gun" is Cuphead's index finger. Bundled with the costume is a direct rip of the track "Floral Fury", the boss battle theme for Cagney Carnation.
A DLC Spirit of Cuphead was added into the game during the special Cuphead-themed Spirit Board event "Ready? Wallop!". It is a Primary Attack Spirit under the Advanced class.
His battle uses Mega Man, who is assisted by three giant Peaches (possibly meant to be the Root Pack) in a Stamina match. The stage is the Omega Form of New Pork City, meant to resemble the Devil's Casino, with the song "Final Results - Wii Party U" playing in the background. To win, only Mega Man must be defeated.
However, if the Cuphead costume has been purchased, the Mii Gunner wearing it will replace Mega Man and the song instead will be "Floral Fury".
- Cuphead is the second Mii Fighter costume character to hail from an indie game, following Sans.
- Much like Sans:
- Super Smash Bros. Ultimate marks the first time Cuphead has been officially modeled in 3D.
- Both of their costumes come packaged with a song.
- Much like Sans:
- Cuphead's segment of the "Mii Fighter Costumes - Round 5" trailer make several references to the game:
- The opening mimics the game's introduction. The picture used inside of the book's first page is meant to match the one from the original introduction, and even uses the phrase "a swell battle", a line used before boss fights.
- A brief clip features the Cuphead costume in Mushroomy Kingdom during a Stamina match, which is meant to emulate the gameplay of Cuphead.
- The characters used in the segment are meant to reference the various bosses; Piranha Plant represents Cagney Carnation, blue Kirby for Goopy Le Grande, green Charizard for Grim Matchstick, and Falco for Wally Warbles.
- The Cuphead costume is the first DLC costume to be used in a Spirit Battle.
- Cuphead is the first Mii Fighter costume character to have a pre-rendered segment in the Mii Fighter Costumes trailer.
- The index finger (rather, the "gun") of the costume is noticeably bigger than its other hand, most likely due to the regular size of the Mii Gunner's Arm Cannon.