Cody Augustus Jones is the great-grandson of April O'Neil and Casey Jones in the 2003 TV series. He is the heir apparent to O'Neil Tech. In the Fast Forward season, he accidentally brought the turtles and Splinter to the year 2105. Later, he created the powerful machine named Turtle X, which he used when participating in the Turtles' adventures. He also learned ninjutsu from the Turtles and Master Splinter.
Cody is slender young man with athletic and slightly muscular build, with red hair and green eyes. In 2105, he wears more futuristic suit and blue pants and white shoes.
In Back to the Sewers, his green eyes are more bright, instead of his white sleeves, they became black as he wears all black pants and shoes.
All his life, Cody had mainly lived inside his penthouse, mainly to protect him from outside influences. When his parents passed away, his uncle Darius Dun took legal guardianship over him and position of CEO of O'Neil Tech.
Cody had always been entranced by artifacts of the past, mostly connected to the Turtles, whom his great-grandparents mention in their journal. He once tried to create a time window to enable him to see the Turtles' exploits but accidentally brought them and Splinter to 2105. He had Serling, his robotic caretaker, to go and retrieve them before they get into trouble. Serling was only able to get everyone but Mikey, who was separated from the others. But thanks to the work of two geniuses (Donatello & Cody), they were able to locate him with his residue temporal signature and rescued him from the Street Phantoms.
The next day, Cody tried to reproduce the same effect for the time window but failed. He needed to repair a damaged circuit board but needed to go to O'Neil Tech to get it. Just then, Darius comes in as the others disappear. Darius lectures Cody over the importance of his safety and that it would be best to stay inside. But the Turtles convinced him to take a slide on the wild side and go straight to O'Neil Tech. So Darius decided to show him how dangerous the outside was by unleashing his Inuwashi Gunjin to capture him. But the Gunjin threaten Cody's life in exchange for their freedom. Thankfully, the Turtles arrive to save him, armed with futuristic weapons made by a transcendental lathe.
Cody continues to befriend the turtles and Splinter, allowing them to live with him in the future while he repairs the time window.
On his birthday, Cody is nearly killed by his uncle but Serling saves him and is heavily damaged because of it. Not wanting to lose his only real family, Cody rebuilds him and fuses him with his mech suit.
Eventually, in Tempus Fugit, Cody is able to repair the time window to send the Turtles back.
He later watches his great grandparents' wedding through the time window, which he got to working properly. He is seen smiling at the event.
Cody possesses a combination of both April's smarts and Casey's hardheadedness. He is a technological genius, capable of creating or modifying highly advanced devices and technology. While he lacks his great-grandfather's physique, he does display Casey's same desire to fight against evil, which Cody does mainly through the use of technology.
Cody is fascinated by his ancestors, particularly their association with the Turtles, which led to his creating a collection of Turtle-oriented relics and the development of the Time Window. However, while familiar with many aspects of their adventures, Cody, like many residents of 2105, is unfamiliar with many of their 20/21st century tastes.
Cody knows turtles as the friends of his great-grandparents, and he accidentally transported them and Master Splinter to 2105 and they decided to stay there for awhile. Turtles and Cody always treat each other like brothers and friends. However, in Race for Glory!, he is sometimes annoyed with them. Cody and Donatello always intelligent and like some gadgets. Leonardo and Master Splinter always train Cody with Ninjutsu skills. Michelangelo plays toys with Cody in The Cosmic Completist. Raphael and Cody team up with each other to save their friends and family and defeat Sh'Okanabo in The Freaks Come Out at Night.
Serling was Cody's caretaker. Serling always took care of Cody, as an infant, child and teen. Serling and Cody always treat each other with respect. In Turtle X-Tinction, on his birthday, he was almost killed by an explosion caused by his uncle Darius Dun. However, Serling saved his life, sacrifices himself, he shows him video slides about their life, causing Cody to broke down in tears. Heartbroken, Cody don't want to give on his friend and vows to fix him, make him better than ever and not only fixed him, but also made him as his new Turtle X
Cody is also good friends with Starlee Hambrath, who is the only living being he is known to have spent time with besides his Uncle Darius before the Turtles ended up in the future. The two have mutual respect and attraction for each other, but Cody in particular is shy about admitting it. However, he is eager to help her in any way that he can, and has shown concern for her at times when she was endangered.
After the death of his parents, Cody's uncle, Darius Dun took the legal guardianship over him and position of CEO of O'Neil Tech. Darius and Cody have a good relationship, but now their relationship becomes strained after knowing that his uncle has been selling the illegal weapons to Zukko and his Triceraton gang, Cody grows with anger and hatred towards his uncle, right before her fires him from O'Neil Tech. Cody's relationship with his uncle Darius ended as both start hating each other.
He knows the Dark Turtles as his enemies as seen in Bad Blood. However, in DNA is Thicker than Water, after their fight, Terrorpin was supposed to blast Cody, but Dark Leo, who has a newfound sign of concern and compassion, he took the blast for Cody, saving his life. Cody becomes bewildered and flabbergasted by this, he then starts owing him, he could give him second chance.
- Genius High-intelligence: Cody has been gifted with an intelligence from his great-grandmother, April. He is shown very skillful of building Time Window, and building Turtle X.
- Stubbornness: Casey has been gifted with an aggression from his great-grandfatger, Casey Jones. In The Freaks Come Out at Night, he's shown controlling his turtle X to fight Kanabo, revealing of how much he is stubborn.
- Ninjutsu skills: Cody has been trained with ninjutsu by the turtles and Splinter.
- In The Day of Awakening Splinter addresses the young man as "Cody-san", a Japanese honorific usually reserved for a older or senior person. Normally much younger persons, particularly ones you are instructing in martial arts, would be "-kun".
- Though this may have been used in light of Cody effectively being their patron while in the future: going out of his way to do everything he could for them even though he was himself in a rather tenuous position.
- By the end of Playtime's Over, it is revealed by Starlee Hambrath that his full name is actually Cody Augustus Jones, his middle name probably being in honor of April's uncle Augustus O'Neil.
- Jason Griffith was initially cast as Cody, and had recorded most/all of his dialogue before being replaced by Christopher Adams.