Serial Designation J or simply known as J, is one of the two secondary antagonists in Murder Drones. Serial Designation J has the distinctive features of a female Disassembly Drone, with wide hips and shins tapered to a point. She has silver hair styled in high-sleek twin silver-colored ponytails, tied with black ribbons. Like other Disassembly Drones, she has neon yellow eyes and a black headband adorned with five additional eyes that contain Nanite Acid and match the color displayed on her visor, as well as a long, thin black tail ending in a large syringe also filled with Nanite Acid. She also possesses jagged teeth. Her attire consists of a short-sleeved black shirt with side pockets under it, a black leather belt giving it as a skirt, a dark yellow shirt beneath her blazer, and a tie, giving her the appearance of professionalism, especially in comparison to the other two members of her squadron. As for her legs, it appears as though she is wearing knee-high stockings with visible suspenders, but this is in actuality just the coloration of her chassis. On her left arm, she wears a yellow armband marked with a skull emblem, signifying her role and identity as a Disassembly Drone. When in combat mode, she reveals jagged teeth, and her visor displays an "X" shape, signaling her aggressive intent. Her appearance is further heightened by large metal wings with a yellow and black color pattern and possesses 16 feather blades, with the middle of these wings being two yellow glowing circles. She is demonstrated to have interchangeable hands that she can switch out for other tools and weapons that can aid her in her missions, one of which are three-sharp claws, which enables her to tear through targets with ease. Serial Designation J has the distinctive features of a female Disassembly Drone, with wide hips and shins tapered to a point. She has silver hair styled in high-sleek twin silver-colored ponytails, tied with black ribbons. Like other Disassembly Drones, she has neon yellow eyes and a black headband adorned with five additional eyes that contain Nanite Acid and match the color displayed on her visor, as well as a long, thin black tail ending in a large syringe also filled with Nanite Acid. She also possesses jagged teeth. Her attire consists of a short-sleeved black shirt with side pockets under it, a black leather belt giving it as a skirt, a dark yellow shirt beneath her blazer, and a tie, giving her the appearance of professionalism, especially in comparison to the other two members of her squadron. As for her legs, it appears as though she is wearing knee-high stockings with visible suspenders, but this is in actuality just the coloration of her chassis. On her left arm, she wears a yellow armband marked with a skull emblem, signifying her role and identity as a Disassembly Drone. When in combat mode, she reveals jagged teeth, and her visor displays an "X" shape, signaling her aggressive intent. Her appearance is further heightened by large metal wings with a yellow and black color pattern and possesses 16 feather blades, with the middle of these wings being two yellow glowing circles. She is demonstrated to have interchangeable hands that she can switch out for other tools and weapons that can aid her in her missions, one of which are three-sharp claws, which enables her to tear through targets with ease.