|Family||Beautiful Gorgeous (daughter)|
|Likes||Inventing, being evil, his daughter|
|Dislikes||Jimmy Neutron and his friends|
|Voice Actor||Tim Curry|
Finbarr Calamitous, better known as Professor Calamitous or simply as Calamitous, is a villain appearing in The Adventures of Jimmy Neutron: Boy Genius. He is a tiny, near-sighted, eccentric, old genius, who is one of the most brilliant evil minds on the planet, and he would be more dangerous if he didn't have the bad habit of never finishing what he starts. Calamitous is determined to get Jimmy to finish his projects for him because he can't finish them himself.
Professor Calamitous was once a brilliant little boy, who never finished anything, from food to sentences. His inability to finish things lead him to never finishing his homework as noted by Ms. Fowl which strengthens the idea he was held back. Later he overcomes this and is heard completing sentences after he took a self-help class (as seen in "Operation: Rescue Jet Fusion," "The Great Egg Heist," and "Jimmy Timmy Power Hour 2: When Nerds Collide"). Calamitous also seems to like Ms. Fowl despite his age. He often wears a lab coat, long black gloves, and eyeglasses. Calamitous has gray hair.
Calamitous also has a robot bodyguard and disguise called the CalamiBot which is also an action figure that Sheen plays with. He appears as quite an odd character. He does not appear much in the series.
He is also the final boss in "Nicktoons Unite!" and "Nicktoons: Attack of the Toybots," where he faced (besides Jimmy and Timmy) Danny, SpongeBob and other heroes, and he appeared in 2006 PC Video Game Called Nicktoons Winners Cup Racing as an Unlocked Playable Character by winning the Grand Prix mode, you'll be able to unlock multiple villains to against, such as Sheldon J. Plankton, Mr. Crocker, and Vlad Plasmius, or you could open other tracks to drive on, such as challenge levels. In a race, Powerups can be acquired other racers. Some of the courses are based directly on the characters in the game. Mini-games is available, but players have to unlock them before they can play them.
- The word "Calamitous" means "Full of Calamity."
- He appears in "The Jimmy/Timmy Power Hour" series when zapped into Dimmsdale, California
- Even after taking the self-help class, there are still times where Calamitous may not finish things, as he admits to not finishing the class. Since he also stated that he meant to finish, it's possible that after "Operation: Rescue Jet Fusion", he did make up for the session he missed and has now completely overcome it.