Mosco Versa-0 is a service machine aboard the starship Edens Zero, primarily tasked with handling chores and maintenance duties on the vessel. He has a medium-sized, heavyset build and a distinctly droid appearance, with two antennas on his head, a large black egg-shaped object resembling a hair bun, a triangle-shaped nose, and small facial features. His black hair is cut to ear length, and his eyes are also black. One of his most unusual physical features is a curious switch located on his belly, which when activated, causes an alternate personality named Cosmo to emerge. Mosco was originally a loyal servant to Sister Ivry, one of the Four Shining Stars who oversee the Edens Zero. However, prior to the main events of the story, he was captured and brainwashed by a fake sister on the planet Guilst, who reprogrammed him to serve as her subordinate. Under this false control, Mosco became a member of the criminal mercenary group Rogue Out. After the battle on Guilst, the real Sister Ivry was freed and Mosco was restored to her side, returning with her to the Edens Zero crew. Sister Ivry affectionately refers to him as the Pig of Edens, and his speech is characterized by his habit of saying Moscoy. In personality, Mosco is fundamentally gentle and loyal. He was programmed for service purposes and shows a fierce devotion to those he follows, especially Sister Ivry. He has a particular fondness for small animals and enjoys their company, though he is known to dislike ghosts. Despite his generally harmless and comedic demeanor, his background includes a past as a mercenary with Rogue Out, though he was not particularly dangerous compared to other members of that group. In terms of abilities, Mosco is an expert sumo wrestler who holds the highest rank of Galactic Yokozuna, and he uses sumo techniques when he engages in combat. He is also capable of flight by rapidly thrusting his arms in whatever direction he wishes to move. His alternate personality, Cosmo, which is triggered by pressing the button on his stomach, appears to be more combat-oriented and may be used when facing machine opponents. Throughout the series, Mosco serves as a supporting character who assists the crew with various tasks and occasionally participates in confrontations. He was present during events such as the infiltration of the Edens Zero by intruders and the search for Labilia, though he has been shown to be relatively weak in direct fights, having been defeated quickly by enemies like Maria Slime or immobilized by gunfire. His role is primarily that of a service droid and a minor combatant, with his most significant story development revolving around his brainwashing and eventual return to Sister Ivry’s service, which solidifies his place as a loyal member of the Edens Zero crew.