Sulu

Sulu (also known as Sulu the Bionic Hamster) is a hamster that was adopted by George Beard and Harold Hutchins. He used to be Melvin Sneedly's pet. Using the Combine-O-Tron 2000, Melvin Sneedly combined Sulu with a bionic robot, transforming him into a cybotic hamster.

He has a hamster voice in the Sound-O-Rama Audiobooks.

Appearance
Sulu is a brown, fuzzy hamster. Beyond his furry exterior is a mechanical exo-skeleton, the source of Sulu's bionic powers.

Personality
Sulu has a lot of heart and is good friends with George and Harold. But his feelings are easily hurt, such as when he spanked Melvin as revenge for insulting and disowning him.

Captain Underpants and the Big, Bad Battle of the Bionic Booger Boy - Part 1
Sulu is Melvin Sneedly's hamster. Melvin used Sulu as his project, transforming him into a cyborg. Melvin wanted the hamster to demonstrate his new powers, but when the hamster didn't do anything, Melvin threatened to spank him with a paddle. With his newfound powers, Sulu spanked Melvin instead. Melvin was so upset that he abandoned Sulu. As everyone left the classroom, George and Harold adopted Sulu. Later, as Captain Underpants failed to defeat the Bionic Booger Boy, Sulu came and defeated the Booger Boy instead.

Captain Underpants and the Big, Bad Battle of the Bionic Booger Boy - Part 2: The Revenge of the Ridiculous Robo-Boogers
Sulu later rescued his former owner and George and Harold from Carl, Trixie, and Frankenbooger, who had been formed from the split parts of the Bionic Booger Boy. Using the Purple Potty, Sulu then went back in time to the Cretaceous period with George and Harold, where they met Crackers. The next day, they attempted to time travel to the past to return Crackers to her home. Unfortunately, as the Purple Potty requires a one day cool-down to operate correctly, it transported them to an entirely different location.

Captain Underpants and the Preposterous Plight of the Purple Potty People
The faulty time machine sent George, Harold, Sulu, and Crackers to an alternate universe, where every aspect of the world is the opposite of the original universe. Misleading them to believe they were their true owners, Evil George and Evil Harold kidnapped Sulu and Crackers. The doppelgängers then hypnotized them.

Captain Underpants and the Terrifying Re-Turn of Tippy Tinkletrousers
It is unknown what became of Sulu in the original timeline where George and Harold were arrested. However, as the bad timeline was accidentally created by Tippy Tinkletrousers due to his misuse of time travel, it is unlikely he was ever adopted at all

Captain Underpants and the Revolting Revenge of the Radioactive Robo-Boxers
Sulu was transported along with Crackers and Tippy Tinkletrousers approximately 13.77 billion years backward in time, where there was no matter yet. Unfortunately, he had gone back in time just when Tippy's thermonuclear bomb was merely seconds from detonation. The bomb then exploded with a "ka-bloosh", presumably killing Sulu, Crackers, and Tippy.

Captain Underpants and the Tyrannical Retaliation of the Turbo Toilet 2000
While Sulu is not physically present in this book, Melvin using a tracker he installed in Sulu's bionic body, he tracked them down to the future and saved them

Later it is revealed here that Crackers' eggs were the result of her mating with him (whom Harold speculates had his genes mutated when he was transformed into a bionic hamster). The resulting creatures are nicknamed "Hamsterdactyls" by George and Harold (as they were still unaware that Crackers was a Quetzalcoatlus and not a Pterodactyl). Crackers and Sulu's offspring are named "Tony", "Orlando", and "Dawn" by the boys. They are instrumental in the defeat of the Turbo Toilet 2000 after his return.

Captain Underpants and the Sensational Saga of Sir Stinks-A-Lot
After the Hamsterdactyls defeated Sir Stinks A-Lot, George and Harold decided to use the Robo-Squid suit in an attempt to rescue Sulu and Crackers from their untimely deaths.

Captain Underpants: The First Epic Movie
In the fun-fair scene, crudely drawn images of Sulu appear as targets for a carnival game.

Trivia

 * A previous version of Dav Pilkey's official website offers an explanation for Sulu's changing sizes, which is related to the Flexo-Growmonic Steel that his cyborg body is made out of.
 * Sulu is named after Sulu the iguana from the Mr. Show episode "The Biggest Failure in Broadway History". This is also the origin of the "BAD SULU" paddle.
 * Melvin reveals he put a tracking device in Sulu's bionic infrastructure, but George and Harold ignore him.
 * It is unknown how Sulu was able to mate with Crackers despite them not being the same species. However, Harold speculates that this is because his genes were mutated during his fusion with the Robotic Endoskeleton.