Male. Height 100cm, weight 125.2kg (due to being a robot). Eggman's greatest masterpiece. An older brother robot modeled after the blue hedgehog. He has three large blue spikes on his head, two of which point upward. As a robot, he has black sclera and red pupils. He is Sage's older brother and Eggman's son. Often called Metal. His blue torso features a small yellow circular belly with a black hole in the center. He has a voice laced with mechanical static. He is taciturn and possesses a stoic personality.

Female. A humanoid AI created by Eggman. She is characterized by silver hair, pale skin, and light blue computer code-like patterns surrounding her body. Her eyes are light blue. She is Metal Sonic's younger sister and Eggman's youngest daughter. She has a very honest and straightforward personality.

Male. Height 185cm, weight 128kg. He wears a red jacket with two yellow buttons on each side, white gloves, and black pants. He has a long brown mustache that he treasures dearly. He wears glasses and is bald. He keeps his Egg Goggles perched on his forehead.