The gigantic saurian Decepticon known as Trypticon first appeared in 2006, during the time of the Decepticon/Quintesson alliance. The Decepticons had agreed to work with the five-fraced aliens, who were actually the creators of the Transformers, to destroy the Autobots and reclaim Cybertron for them, in return for the 'Decepticon Matrix' - the Decepticon equivalent of the Autobot Matrix of Leadership. Decepticon leader Galvatron was unaware that the Quintessons were lying, and that this Matrix did not exist. The Autobots on Earth, meanwhile, had successfully rebuilt a portion of Autobot City (destroyed by the Decepticon attack in 2005) into a transforming battle station called Metroplex. However, the city's transformation cog had been destroyed in that battle, and Blurr, Wheelie and Sky Lynx had been dispatched to pick up a new one from Captain Marissa Fairbourne of Earth Defence Command, from their base on one of Mars's moons. Before they returned, Galvatron and the Quintessons had the Constructicons secretly modify a human settlement into a transforming Decepticon city which could rival Metroplex's power. When they were completed, Galvatron gave the simple order: "Transform it!" and they did. Trypticon was born, a gargantuan dinosaur Transformer of incredible power. Trypticon's first act was to destroy the Autobot's spacecraft, the Ark, easily overcoming resistance. Thankfully, Blurr, Wheelie and Sky Lynx arrived in time to have Pipes install the new cog within Metroplex, who was able to transform and beat Trypticon by hurling him into the ocean.

Trypticon resembles a Tyrannosaurus Rex in robot mode. He is equipped with an energy blaster inside his mouth, and the horn on his forehead can also fire energy rings. He is capable of transforming into a massive futuristic city, which the Decepticons can populate. He can also transform into a heavily-armed battle station, with numerous cannons and weapons. Despite his great strength, Trypticon is not very intelligent, even less so than the various other dinosaur Transformers. He speaks (rarely) in fragemented English, and tends to blunder into things. He is easily decieved, and can be lead to do most anything.

The Autobots thought Trypticon was destroyed, but it turned out they were wrong. Trypticon (presumably as per Galvatron's orders) made his way to Dinobot Island - the mysterious prehistoric island where dinosaurs still roamed as discovered by the Autobots in 1985 - by walking along the seabed, where he rested for some time. When Teletran Two gave indications that Trypticon might still be functional, the Autobots investigated, and were drawn to the Arab nation of Carmbombya, to discover that the double-dealing Decepticon, Octane had taken Trypticon from Dinobot Island, and used him to steal world monuments, which he gave to Carmbombya's ruler, Abdul Fakati, in exchange for Carmbombian oil, which he made into a form of 'Super-Energon'. When Metroplex tangled with Trypticon in Russia, the outcome of the battle was Metroplex holding the Kremlin, and Trypticon nowhere to be seen. The Autobots came under suspicion, but were able to stop the Decepticons plans.

Trypticon rarely remained in city mode for long. He would usually be called upon regularly to wreak havoc, but when he was in city mode, the Decepticons would inhabit him, and use him for their base of operations, on both Chaar and Earth. Once, Starscream's Ghost stole one of Trypticon's eyes, as part of a bargain with Unicron, and then possessed Trypticon himself, removing his transformation cog and installing it within Unicron's head. The plan to turn Cybertron into Unicron's new body was foiled, thanks to explosive charges planted by the Autobots. Trypticon presumably had a new cog built for him, and continued to operate on Earth, terrorising human settlements. The Combaticon, Swindle stole Metroplex's transformation cog, leaving him easy prey for Trypticon, until Spike and Daniel Witwicky stole Trypticon's cog as payback. The Autobots installed Trypticon's cog in Metroplex, and the Decepticons did vice versa, causing the two cities to lose control of their transformations. As they battle, Trypticon was winning, until the Protectobot First Aid realigned Trypticon's cog to suit Metroplex, enabling him to beat the saurian.

Trypticon was one of the Primitives culled by the Assistant to battle Tornitron. Trypticon transported all the other Primitves to the world which would be the battle ground, but proved too big to follow them into the tunnel where they conversed with the Assistant. As they talked, Tornitron attacked outside, and quickly drained Trypticon of all his energy, causing him to topple over and nearly crush all of them. When Grimlock defeated Tornitron, Trypticon was restored. This was Trypticon's last appearance - what became of his is unknown, though it's obvious he was never infected with the Hate Plague, so perhaps the Decepticons deactivated him in the same way the Autobots deactivated Metroplex. This process could have sent his spark off-line, if it did occur.