MOLLY is the devious and cunning oldest SLIME SISTER, appearing somewhat passive aggressive and sometimes flirtatious. She often addresses people as "darling" and has a laugh that sounds like "fufufu." As a scientist, MOLLY seems to prefer working with metal. She puts dangerous puzzles and traps around her lab to counter her younger sister MARINA's attempts to steal her stuff, which can disturb her HUMPHREYS' work, much to their annoyance. According to HUMPHREY, she loves to play games too much and could probably do much good for the world if she would focus, as she sabotages their experimental data for the fun of it. Unusually, her CONVEYOR-BOTS dislike polite people and are accustomed to people being rude to them, as it reminds them of MOLLY. MOLLY describes herself as a busy person whose work takes patience and appears skilled. She is actually extraordinarily lazy and prefers computer sciences and technology as her medium due to the minimal amount of movement required to create her experiments. When it appears HUMPHREY is going to eat her and her siblings, instead of planning escape she accepts her fate without a fight, noting she was already tired from the earlier fight. Later when she loses her body and is reduced to just a head, she ends up finding it convenient and wishes she had thought of it sooner, as it's less to drag around with. She is also quite fond of cheesy potato chips, which are stereotypically considered something that lazy people are fond of. She can deceptively appear gentler than her sisters and at times seems to look out for her easily frustrated younger sister MARINA. After the gang is revealed to lack the money needed for their payment, she says she likes the quiet one (OMORI), and wishes to keep him as a pet, opting to sell KEL for profit. Despite attacking the children, she later apologizes for her earlier behavior and states the sisters tend to get too carried away. Though preferring technological sciences, she doesn't understand some basic codes and blames her laziness on others on occasion. MOLLY is stated to find enjoyment in everything, including pain, as she smiles elatedly when getting hurt during battle and excitedly states that she is having "so much fun" and had been looking forward to another "hunt."