The Evil Syndicate was formed when Professor Finbarr Calamitous stole the plans of an inter-dimensional portal through a flea-bot on Jimmy Neutron's pet dog Goddard. He used the portal to get access to different worlds and drain their energy with the help of each world's villain. In response, Jimmy assembled each world's heroes to fight the syndicate and stop their draining. They passed through Amity Park, Bikini Bottom and Fairy World before learning of The Syndicate's true plan: to build a Doomsday Device that can destroy a world in a matter of seconds. Once the villains were defeated, Calamitous called them back to attack the heroes all at once. But, even together the heroes managed to defeat the villainous group and shut down the machine, sending their villains (each one trapped somehow) back to their home worlds.
- Members: Professor Finbarr Calamitous (Leader and founder), Beautiful Gorgeous
- Type of energy: Electromagnetic energy
- Respective Heroes: Jimmy Neutron
Amity Park/Ghost Zone
- Members: Vlad Plasmius, Technus
- Type of energy: Ghost/Ectoplasmic energy.
- Respective Heroes: Danny Phantom, Samantha Manson