OnionHead is a small Onion-Like alien. He has three crab-like feet on either side and behind his body, and large stalks sprouting from the top of his head. He wears a black suit on his mouth with green and white details.
The Omnitrix symbol is located on his face.
- Enhanced Intelligence- OnionHead possesses a high intellect that allows him to understand, create and operate advanced technology.
- Noxious Spores- OnionHead is able to emit spores from his mouth that when inhaled cause an intense burning sensation on the eyes, mouth and nose, eye-watering, and blurred vision. If high quantities of spores are released at a time, they can generate a smokescreen effect.
- Sprout Overgrowth- OnionHead can manipulate the stalks located on top of his head, being able to move and increase them in size at will.
- Speech Incapability- Onionhead's language is unable to be translated, creating a communication disadvantage with other life forms.
- Physical Limitations- Onionhead's simple limbs lack any fine motor skills for their lack of digits, significantly impairing him from reaching his full potential in machinery building.
Nogrog was visited by the Eradicators, and, deemed to be a threat to the Kryptonian hierarchy, was promptly attacked.
- OnionHead shares a home planet with Callus, however the two species are unable to communicate due to a language barrier.
- A Sanavox is able to translate OnionHead's language, but because of the advanced vocabulary he uses, they would not understand what he is talking about most of the time.