Traximus was once an honorable warrior of the Triceraton Republic who believed that its old virtues should be restored and openly questioned the new destructive ways of the depressing Triceraton Republic under the rulership of the dictatorial Prime Leader Zanramon before the Triceraton High Council. He was convicted of high treason, and at the orders of the tyrannical Zanramon, wound up in the gladiator cells with warriors beneath the "The Games"' stadium. He was left to rot in his despair in order to eke out his last days as an enslaved Gladiator.
In his captivity, years of fighting almost made him forget about his people's honor, but that sense of honor was re-sparked when the Turtles themselves, who were thrown in the Games under Zanramons command, to further "persuade" their new friend Professor Honeycutt to build his latest invention, the teleportal, to the services of the Triceratons, came crashing in and were forced to fight the other gladiators at the behest of the whipper, Gruell. All the gladiators lost, and the Turtles proved their devotion to help their own, gaining the respect of the other gladiators, especially Traximus who was bested by Leonardo, who spared his life with honor. Inspired by this act of kindness, Traximus regains his will to live and hope that the current dictatorship can be overthrown. When Gruell was serving their last meals - literally their last meals - Traximus and his fellow gladiators gave the Turtles a portion of theirs.
When the next Games were being held, Traximus refused to fight, as did the others. Control units scrambled to separate the gladiators from the Turtles, but they managed to escape the arena in the confusion following the Turtles' flight, stole a shuttle and finally escaped the Games as the Republic and the Federation battled over the Fugitoid.
Later Traximus participates in the Battle Nexus Tournament, but not like most other fighters for glory's sake, but to eventually recruit warriors to assist him in overthrowing Zanramon's corrupt government. While competing in the Big Brawl, Traximus met the Turtles again, fought against Raphael and lost. After Raph lost to Michelangelo, he began freaking out, so Traximus took him out for a drink. After telling his story, Traximus commented that he had heard that someone, a rat, had assaulted the Daimyo. Raphael suspected that his master Splinter had been set up (which was in fact true, due to the Ultimate Ninja and Drako's machinations), and the two of them set out to free him. Raphael and Traximus penetrated the Daimyo's castle, freed Splinter from the Daimyo's son, and met up with the others and the recovering Daimyo. They went into the Battle Nexus ring, which was being cast into turmoil by Drako, who was fighting with the Ultimate Ninja over control over the War Staff. Unfortunately, the staff inadvertently opened a dimensional rift in time and space that would consumed all that was sucked into it. Traximus managed to anchor himself to the ground with his axe, giving most of the others a safe base to hold onto, before the Daimyo managed to close the rift.
After these events, Traximus, along with two other Battle Nexus participants, secretly returned to the Triceraton homeworld, learning that Zanramon was pushing the Republic to the farthest edges of the universe in search of Honeycutt. Traximus was able to gather a significant number of dissidents who had grown tired of Zanramon's rule and hid his forces in the abandoned tunnels riddling the core of the homeworld.
In the third season, during the Triceraton invasion of Earth, shortly after they arrive on the Triceraton homeworld Traximus and his resistance fighters made contact with the Turtles, who had come to rescue their brother Donatello, who had been captured and was being interrogated about the Fugitoid's whereabouts. With the help of Traximus' ally, Monza Ram, Donatello was sneaked away from Zanramon. When the entire Federation fleet and some of the Triceraton Armada was disabled by Professor Honeycutt's computer virus, Zanramon jettisoned the ultimate principles of honor and ordered an attack against his helpless enemies, but just then Traximus' men infiltrated the command center and gained Commander Mozar's assistance in carrying out the coup d'état. The great war-mongering leaders of both sides were deposed, and Traximus destroyed Zanramon's throne, erasing the last remnant of the tyranny which had disrupted the Republic, restoring it to order. At the end of the six-part story arc, Traximus has finally overthrown Zanramon and declares the war with the Federation to be over, expressing his wish for a new age of peace and honor to begin, with no further absolute rulers as Zanramon was. Traximus then returned the stranded Federation troops to their territory as a first gesture of peace - except for their leader General Blanque, who remained along with Zanramon in custody as not to disrupt the peace process.
Traximus has a strong sense of honor and loathes what the Triceraton Republic became under the leadership of Zanramon. He shows defiance by speaking out against Zanramon but during the time where he is forced to fight as a Gladiator, he loses heart until the Turtles arrive and remind him that some people still possess a sense of honor. Traximus regains his determination to overthrow Zanramon and once again displays his defiant nature by refusing to attack his new friends in the Triceraton Arena.
Unlike most participants in the Battle Nexus Tournament, Traximus is not interested in winning but merely in recruiting warriors to help him in his mission to restore the Triceraton Republic. When Raphael decides to break Splinter out of prison, Traximus warns him that it is a foolish idea, before cheerfully adding "Count me in". In addition to being a loyal friend, Traximus also shows that he can be forgiving, holding no grudge against Mozar for his service to Zanramon and even making him his right hand man after Mozar proves that he still possesses his sense of honor.
- "Turtles in Space - Part 4: The Arena"
- "The Big Brawl, Part 1
- "The Big Brawl, Part 2
- "The Big Brawl, Part 3
- "The Big Brawl, Part 4
- "Space Invaders, Part 3"
- "Worlds Collide, Part 3"
- He may be based on Maximus Decimus Meridius, the main character of the movie Gladiator (2000), a Hispano-Roman general who is betrayed and ends up as a gladiator. Another similarity is with the historical figure of Spartacus (d. 71 BC), a Gladiator who led a slave uprising against the Roman Republic.