Min Min appears mostly human except for her spiraled irises and her ramen-like hair and ARMS. She has green eyes, blonde hair with straight-cut bangs and a fringe, along with an orange mask. Slices of narutomaki are attached to the upper part of her noodle arms. When fully charged, her left noodle arm transforms into a dragon. She wears an orange beanie shaped like an upside-down ramen bowl, an orange athletic shirt, orange athletic shorts, black calf-length leggings, and green sneakers.
Other outfits she wears includes a chef-like version of her outfit consisting of an orange shirt with a small bowtie on the collar, matching shorts and orange leggings as well as an apron with her logo on it and black flat shoes, a white sweater revealing blue bra or undershirt straps and blue jeans along with two of her badges pinned to her hat, as well as a dark orange kimono with white fur on the top, a yellow bow in the back, and a pair of black zōri with orange straps. She's also shown to wear her hair in a ponytail with a green hairband and into a loose bun held by a green chopstick with a narutomaki on it.
Min Min is one of a select few people in the world to be born with a gene causing ARMS, a phenomenon where the person's arms (or, in some cases, other body parts) turn into long, stretchy material. In Min Min's case, her ARMS seem to be made of ramen noodles, due to her family operating the famed Mintendo Noodle House. Her left arm can also transform into a dragon arm when fully charged, keeping the ARM equipped to it charged and increasing its power until she gets knocked down. In addition to her ARMS, she also kicks, which enables her to deflect opponents' punches. Min Min competes in the ARMS League to promote her family's restaurant.
An ARMS representative was announced to be added as DLC on March 26th, 2020, but it was not until June 22nd that this character was confirmed to be Min Min. Her extendable ARMS give her a unique control scheme and play-style that encourages playing on the ground from a distance but is at a disadvantage in the air and in close range. She was released as part of Challenger Pack 6 on June 29th, 2020.
Prior to the game's launch, Masahiro Sakurai considered adding characters from recent Nintendo titles such as ARMS and Xenoblade Chronicles 2 in the base roster, but he was unable to do so because they were announced long after planning and production of Ultimate began. When it came time to develop a second wave of downloadable content for the game, Sakurai considered Min Min and Ninjara as possible candidates and, following a request from ARMS producer Kosuke Yabuki, the position went to Min Min.
Despite her status as downloadable content, Min Min does have a legitimate role in World of Light, as she appears in the base game as a spirit that can be found in the Light Realm, as one of the two spirits the player can beat to get to Lucas, meaning that she was vaporized by Galeem. Defeating this spirit does not unlock her as a playable character; rather, she is unlocked after downloading her and defeating at least 10 other fighters from Galeem's control, just like other DLC characters. The Min Min Fighter Spirit can be obtained by completing Classic Mode. It is also available periodically for purchase in the shop for 500 coins, but only after she has been downloaded. Unlocking her in World of Light allows the player to preview the second spirit below in the Spirit List under the name "Min Min (Fighter)". Additionally, Min Min has an Attack-type Primary Spirit as part of Ultimate's base game.
- Min Min is the first DLC newcomer in any Smash game that came from a new first-party series.
- Min Min is the first playable character in the Super Smash Bros. series to have Chinese voice lines. She is also the only character to speak a real-life language other than English or Japanese in all regions of Ultimate.
- Min Min is the fourth fighter to originate from a fighting game, following Ryu, Ken Masters, and Terry Bogard. Of these four, she is the first female character and first-party character to come from this genre. She is also the first to debut in a 3D fighting game.
- Min Min is the second fighter to originate on the Nintendo Switch, after Byleth.
- Min Min's flurry attack bears a slight resemblance to Chun-Li's Hyakuretsukyaku in Street Fighter; Coincidentally, Min Min and Chun-Li are both Chinese female characters from fighting games.