- "A robot that takes care of its master. Cooks, cleans, does laundry, cleans out ears and trims nose hair."
- — Battle Memory
- "IF YOU TAKE MASTER KING P'S VERY PRECIOUS "FRIEND'S YO-YO" I WILL BE MAD. MAD! MAD! VERY MAD MAD MAD MAD!!!!!!"
- — Li'l Miss Marshmallow (before battle)
- "YOU REAP WHAT YOU SOW SO SEW SO-SO GREETINGS CHEESE POPSICLE THE NUMBER YOU HAVE DIALED IS CURRENTLY OUT OF PORK CHOPS FROM EAST TO WEST IT GOES GOES BROKEN BROKEN OH SO SOW SEW BROKEN *whir* *clank* *clunk*"
- — Li'l Miss Marshmallow (after battle)
Li'l Miss Marshmallow (マシュマロちゃん Mashumaro-chan) is an optional boss in Mother 3. She is King P's robot maid, who bears a resemblance to Electra, Pokey's human maid while he worked as a business consultant for Geldegarde Monotoli in EarthBound. It is possible that Li'l Miss Marshmallow was designed in Electra's likeness.
During the party's escape from Fassad and two other Pigmasks, they come upon a room inhabited by Li'l Miss Marshmallow. If spoken to, she reveals her name and that the room belongs to "King P". The battle is avoidable and is not required to complete the game: she only initiates battle if Lucas and co. attempt to touch the yo-yo in the northwestern part of the room, causing her to yell at him before the battle begins. When she sustains enough damage in battle, Li'l Miss Marshmallow activates her Ultra Ticked-Off System which changes her sprite and allows her to use stronger attacks that hit all party members, rather than being restricted to single targets. As a machine, she can be affected by a Saltwater Gun.
Once she is defeated, she slumps, sways, and falls to the ground before yelling nonsensical phrases and exploding. After this, the party automatically takes the Friend's Yo-Yo from its case. The fight against Li'l Miss Marshmallow can be avoided by simply not examining the yo-yo in King P's playroom, however defeating her in battle is the only way of being able to obtain the Friend's Yo-Yo.
Her battle sound is Battle Sound 51 which falls under Code Numbers 912 for regular attack, 913 for Smaaaash! and 914 for Miss.