Evil Jimmy is one of Jimmy's clones created in the "Send in the Clones" episode.
Evil Jimmy looks almost exactly Like normal Jimmy, with brown hair and a large head, and is dressed exactly the same as him. He wears a red shirt with a yellow atom design, blue pants, a wristwatch, and a pair of white converse sneakers.
The only differences between the pair are that his hair is split in the center curled into two horns, and his eyebrows are spiked.
He was the last of the 6 clones created to do chores for Good Jimmy, though he was the one that was Jimmy's moral opposite and he caused trouble and tried to trick the other the clones that he's the real Jimmy, but that backfired when Jimmy iced his clones. Unfortunately, Evil Jimmy managed to escape on Jimmy's jetpack before Jimmy could stop him, leaving Good Jimmy in big trouble with his friends, despite the fact that Jimmy didn't do anything wrong.
In "The Trouble with Clones", he is revealed to have created a rocket bike which he used to fly in Earth to make prank calls all over the Earth after hijacking the communication satellite. Jimmy eventually attempts to turn Evil Jimmy good, though he fails due Evil Jimmy breaking the de-evilizer, and Evil Jimmy just pretends, until he is able to use a camera known as 'The Duplicator' in order to clone the Earth, resulting in the real planet to slowly fade away. Luckily, Evil Jimmy screened himself and the real Jimmy out of the cloning process (figures, Evil Jimmy doesn't want more Jimmy's running around) so he took off on his rocket to reverse the effects. However when he got there, Evil Jimmy made the planet just as evil as he is thanks a Dark Matter Power Chip placed in the device. There, the environment is dark, chaotic and Jimmy's friends and parents are as evil as Evil Jimmy. Jimmy was able to confront him and reverse the process preventing the real Earth to fade into oblivion. Enraged at this, Evil Jimmy snaps the dark chip in half in an attempt to trap the real Jimmy with him on the cloned Earth in the Dark Matter Dimension before it could fade. Jimmy escaped and Evil Jimmy vowed to return.
In the planned season four premiere episode, "Deep Impacts", Evil Jimmy would've escaped from the Dark Matter Dimension along with the other evil clones and attack Jimmy and his friends, who were on a field trip to an asteroid (provided by Jimmy himself, of course), which would've led to his official defeat. Unfortunately, since DNA Productions shut down before the season could be produced, it is left up to the fans to speculate what happened to him after the series' end. It is most likely that he's still trapped in the Dark Matter Dimension or dead, though there is an extremely small chance of him escaping and wreaking havoc on anything or anyone he touches to get revenge.
- His hairstyle resembles devil horns unlike his good counterpart.
- Despite having some humorous quirks, he is without a doubt, the most evil villain to come out of the franchise.
- Evil Jimmy's voice is the same one Rob Paulsen used for the main character in The Mask animated series, which coincidentally is based on the Jim Carrey film of the same name. His catchphrase "Oh Mercy!" also references The Mask. His voice is also a take on Jack Nicholson.
- He could make his voice sound like Jimmy's, as he did in Send in the Clones to try to confuse Jimmy's other clones, but he never used this when he was passing off as him in The Trouble with Clones.
- Evil Jimmy is the only evil clone not to have the same voice actor as the original.
- It is unknown why he is not part of the League of Villains, but it was most likely because he was still trapped in the Dark Matter Dimension.
- "Catch ya on the flip side, 'Whippy-Dip'!" (evil laughter) -The Trouble with Clones
- "Looks like a pile of donkey dandruff to me, 'Chief'..." -The Trouble with Clones
- "Ya can't beat the classics!" -Send in the Clones
- "Well, well, well... If it isn't Jimmy, Jimmy, Jimmy, Jimmy, Goddard, and Jimmy..." -Send in the Clones
- "Hey, Sir Francis Bacon, more fudge swirl!" -The Trouble with Clones
- "Nice place, kid! I could have some serious fun with this stuff... (laughs mischievously) -Send in the Clones
- "You two think you're two sassy backup singers!" -The Trouble with Clones