The Empire's reign was upset during an attempt to capture Professor Honeycutt, a robot scientist who had befriended the Ninja Turtles. Hoping to steal the Professor's teleporter device, the Triceratons became embroiled in fresh battle with the Federation. During this time, they captured the Turtles and sent them first to prison, then to the gladiatorial matches.
It was in these barbaric surroundings that the Ninja Turtles met Traximus, a noble warrior of the Triceraton Empire. He had been thrown into the games when Zanramon took over, and sought to break free. With help from the Turtles, who stole Zanramon's cruiser and then escaped back to Earth, Traximus and co. escaped. Traximus next appeared in the Battle Nexus, competing and looking for allies. He helped the Turtles in a fight against the evil Drako. Curiously, Traximus did not require a breathing mask in the Battle Nexus, for reasons which remain unknown.
The Triceratons trailed Honeycutt to Earth, where they invaded and did battle with the Turtles. They captured Donatello to extract the information. But Donatello didn't know where Honeycutt was. However, once it was determined that the professor had left Earth, the aliens departed. Unfortunately, Honeycutt just then returned, sparking another conflict between the arriving Federation and the returning Triceratons. However, Honeycutt managed to end the battle by infecting both sides with a virus. Zanramon ordered the Federation ships destroyed but any ship coming would be affected too. Commander Mozar thought it was not honorable.
It was then that Traximus' rebellion attacked. Dethroning Zanramon with the support of Commander Mozar, Zanramon's second-in-command, Traximus destroyed the leader's chair to symbolize the end of the empire and revealed that a Triceraton senate will replace the dictatorship. He then helped the Federation, and Zanramon and General Blanque, the former leader of the Federation forces, were both imprisoned to help ensure the peace.
In the Fast Forward season, a few Triceratons were seen as workers on Earth.
Triceraton technology is quite advanced, employing anti-gravity vehicles and energy blasters on a regular basis, on about the same level as the Federation. A notable trademark of Triceraton technology is the common triangular or pyramidical design on many vital systems, such as power cores and blasters.
The Republic was once a society of honor and glory, but with Zanramon takeover, the Republic lost the sense of their warrior's history transforming into the Empire. But thanks to Traximus, the old Republic was restored.
On one of the homeworlds, there is a place called "The Games", where helpless beings are pitted against each other for fun. But Triceraton gladiators is also available to the Federation, which is their number one show.