|Body||Robotic Planetary Humanoid|
|Alternate Counterparts||Ultimate Gravatomix (Ultimate Form)|
|Powers and Abilities|
Fusion Energy Manipulation
Gravatomix's body shape is mainly that of Gravattack, and is covered in reddish-brown rocky skin, but his underside has Atomix's colors, with his molten core being replaced with an Omnitrix-like symbol filled with the same energy as Atomix, large canisters on his arms with that same energy, the same "chin" as Atomix, but changed to fit his more Gravattack-like head, and Atomix's legs. The Biomnitrix symbol is on his belt.
Powers and Abilities
Gravatomix has the powers of Atomix and Gravattack, allowing him to generate and manipulate his own nuclear energy, as well as absorb other sources of nuclear energy. Gravatomix can also control gravity and even become a small planet. By combining his nucleokinesis and his gravikinesis, he can create a small black hole, which he has control over.
Gravatomix has Atomix's overconfidence, and Gravattack's large size. Sudden changes in mass can throw off his gravikinesis, and too much damage to his core can cause it to explode.