debuted in Turbo-Charged.
After Terrorax managed to obtain the portion of Maxwell's T.U.R.B.O. Energy, he went to his hideout to show Lord Nexus. After doing so, he puts the portion in a device that transforms it into Terror Energy and states that they now could generate endless quantities of that energy. He end the conversation with Nexus' motto, "We are Legion, We are One, We are Nexus!".
Much later, Terrorax appears talking with Nexus, who said that he had understimated Max and his team. The villain presents a trio of mutants and gives a brief description about their past before charging them with Terror Energy. Shortly after doing so, he sends them to fight against Max's Team Turbo.
After Max and his team invades Terrorax's hideout, he sends Team Terror to fight against them. Meanwhile, Terrorax executes his plan of disabling the technology from Copper Canyon and eventually manages to do so. After Team Terror is defeated, Team Turbo manages to temporarily take down Terrorax. Max charges the devices with his green T.U.R.B.O. Energy and brings the electricity back. After seeing this, Terrorax gets extremely angry and decides to finish off Max once for all, but he forces the creation of Turbo Armor Mode and gets defeated instead.
After the villain is finally taken down, the hideout starts to countdown for destruction, and Terrorax is left to perish. Team Terror, however, is rescued by Max's team.