Trannis was the Deception leader before Megatron, who appears in both the Transformers: Generation One cartoon and comic.
Trannis was an early Decepticon built by the Quintessons as a military general to lead the military hardware. He and his forces presumably took part in the war to overthrow the Quintessons to win freedom and independence for the Cybertronian race. After the war was over, Trannis renamed the Military Hardware, the Decepticons whilst the robots built as Consumer Goods renamed themselves the Autobots. However either due to his origins as a war machine or just a "might makes right philosphy" in general, Trannis desired conquest. Trannis organized the Decepticons into an army and rebelled against the civilians he was meant to protect; demanding the Autobots cede complete control over the planet to them and help them in their quest to conquer the galaxy or be destroyed. The peaceful Autobots refused the Decepticons demands resulting in a gigantic war for the planet. The Decepticons immediately had the advantage due to their bodies being built for warfare and their massive arsenal of weapons. Trannis easily killed the Autobots then leader, Guardian Prime, in a massive attack. With the Guardian Prime's successor, Zeta Prime dying to the Decepticons, not much later, Trannis's tyranny over Cybertron seemed inevitable. However just when all seemed lost, Sentinel Prime proposed to use Stealth to defeat the Decepticon's firepower and the Autobots invented the art of transformation. With this Sentinel Prime was able to lead the Autobots to sneak up on unsuspecting Decepticons. Finally Sentinel Prime met Trannis on the field of battle and defeated the Decepticon Tyrant. Trannis was presumably destroyed or imprisoned for his crimes. With the defeat of the Decepticons, Cybertron entered a Golden age of prospertiy. Unfortunately many hundreds of years, the Decepticons found the secret of transformation and the great war between the Autobots and Decepticons was reignited by the latter's new leader, Megatron, who then proceeded to assassinate Sentinel.
In the UK Marvel Comics, Trannis was a Decepticon warlord who took over the Deception forces on Cybertron when Megatron was stranded on Earth. Under Trannis ruthless campaign of terror, the deceptions managed to undo all the work the Autobot had done on Cybertron. However despite his success, Trannis was unable to conquer the Autobot capital, Iacon. after hundreds of years failed conquest, Trannis decided to simply burn Iacon to the ground by leveling it with Decepticons weapons. The Autobot council, outside of Emirate Xaaron, decided to surrender to Trannis to prevent total destruction of their beautiful city. Xaaron's decision proved a wise one as the merciless Trannis proceeded to execute all council members and burn the city anyway. Xaaron mounted a resistance and in time, the resistance managed to kill the wicked Trannis. Trannis would be succeeded by Straxus.
- The cartoon incarnation of Trannis was not dentified as such in the cartoon, and would only be named as such in the Ask Vector Prime Facebook page.