Jimmy Negatron is an evil version of Jimmy Neutron from another dimension. He only appears in the video game titled "Jimmy Neutron vs. Jimmy Negatron."
Negatron looks just like Jimmy, except he has a goatee and wears a mad scientist outfit.
- Negatron's goatee may have been inspired by the Star Trek episode titled Mirror Mirror, in which the evil version of Spock has a goatee.
- Negatron was originally going to be a character on the show and his name was gonna be "Nummie Jetron", but that role was given to Evil Jimmy.
- Though it is never confirmed, Negatron's full name is most likely James Issac Negatron.