Biographical information
Home Earth (current)
Cybertron (former)
Aliases The Devourer
Nickname Unknown
Occupation Wanted Criminal
Afiliation Decepticons
Abilities Aliment Empowerment
Weapons Muscles
Mentor Unknown
Pupil Unknown
Physical description
Species Cybertronian


Gender Male
Hair Unknown
Eyes Red
Alt Mode Underbite2
Out of universe information
Voice Liam O'Brien
Debut "Pilot (Part 1)"
Underbite is a huge Decepticon that resembles a gorgonopsian, an extinct dog-like reptile. He seems to have a rivalry with Grimlock. He transforms into a futuristic Cybertronian tank-like vehicle. He is classified as a Chompazoid and can devour almost any metal, which increases his strength. He's even gone so far as to name his forearms "Thundercruncher" (right) and "Boltsmasher" (left).


Underbite was apparently arrested for destroying Nuon City, and was incarcerated aboard the prison ship Alchemor. After it crashed on Earth, he was freed from his stasis pod by the impact, and set off in search of food. He eventually encountered Sideswipe, and after a brief chase he tangled with the rest of Bumblebee's team. After spying a nearby scrapyard through the trees, he headed off to devour that instead.

Despite tussling with Grimlock, Underbite began chowing down on the contents of the scrapyard, only to spot a bigger prize—nearby Crown City. Unfortunately, the organic matter he encountered along the way was unsuitable for his consumption, and he slowly weakened. Using metallic bait, the Autobots managed to lure him to the edge of a quarry. Underbite managed to outfight them and prepared to munch Denny Clay's pickup truck. Fortunately, a ghostly Optimus Prime intervened and helped defeat the Decepticon. The Autobots later placed the incapacitated Underbite back in his stasis pod.

Underbite's stasis pod was stolen by Grimlock while the Dinobot was under the control of Minitron. Although the other Autobots were able to free Grimlock from the cyber-tick's influence, Steeljaw, who had masterminded the heist in the first place, made off with the stasis pod and reactivated Underbite.

Now a member of Steeljaw's gang, Underbite was hanging out at the Decepticon hideout with Fracture when Steeljaw arrived with newcomer Clampdown. After Clampdown fled due to Thunderhoof threatening him, the other Decepticons tracked him to a garbage tip where they encountered the Autobots. Underbite fought with Grimlock, however this time the Autobot managed to take him out- first by force-feeding him plastic and then cannonballing him. Steeljaw later freed the gang, and they escaped back to their hideout.

Underbite took part in an attempt to free the prisoners in the Autobots' scrapyard. After Streeljaw trapped the Autobots outside using subsonics, Underbite was given the task of guarding the prisoners, only for them to escape while he was eying up some nearby scrap as potential food. Once the Autobots regained access to the scrapyard, Underbite was swiftly taken down by Strongarm and later fled back to base with the rest of Steeljaw's gang.

Out collecting parts for the device Steeljaw's mysterious friend wanted them to build, Underbite and Thunderhoof happened across Sideswipe and Strongarm, promptly capturing the pair with Fracture's help. When Windblade flew over the steel mill hideout, Underbite was able to bring her down with a precisely thrown beam, adding her to their collection of hostages. The Decepticons were soon busy at work constructing the gateway Steeljaw's ally required, however when Bumbblebee and Drift arrived, Steeljaw assigned Underbite and Thunderhoof to intercept them. Underbite swiftly dealt with Drift, allowing Megatronus to arrive on Earth. He and the other Decepticons were rendered unconscious when Optimus Prime tried to interfere with the arrival.

They came around in time to prevent the Autobots getting hold of Megatronus's staff, however when Megatronus turned on Steeljaw, Underbite, Thunderhoof and Clampdown attempted to flee. They ran straight into Team Bee, and Underbite was taken out when Bumblebee cannonballed into him. The defeated Decepticons were later stored away in stasis pods.

Following the defeat of Megatronus, Underbite was among the Decepticons who were freed by Steeljaw and set to work mining energon for their new empire, though he hated being underground as people kept sneaking up on him. When Team Bee turned up, Underbite tackled Grimlock.


TV SeriesEdit

Season 1 Edit

Comic SeriesEdit




  • Underbite remains the only Cybertronian in Steeljaw's Pack to retain his Cybertronian vehicle mode.