Underbite

====Season 1====
[[File:Underbite talk.jpg|250px|thumb|left|Underbite talking with Sideswipe.]]
Underbite made his first appearance in the show in the first episode. Underbite was one of the prisoners on the [[Alchemor]] before it crashed on Earth. He manages to escape from his stasis cell and goes around the area that the shipped had crashed on. He soon discovers [[Sideswipe]] and [[Russell Clay|Russell]] in a Canyon where he roars ferociously at them. Sideswipe introduced himself to Underbite and Underbite asked him if he knew a city called "[[Nuon City]]". Sideswipe did not know and Underbite stated he ate the whole city. Underbite attacked them and ate an abandoned car for boost before chasing Sideswipe and Russell. Underbite caught up to them when Sideswipe transformed into his cyber-vehicle mode. Underbite stated it won't matter then he chased them again. Underbite caught up with [[Bumblebee]] and [[Strongarm]] who immediately opened fire on him. Underbite chases all four of them back to the crash site and Underbite fought the Autobots as Russell and Fixit hide behind a stasis cell. Underbite managed to dispatch the Autobots, eat some parts of his old stasis cell and found Grimlock trapped in a stasis pod. Grimlock asked Underbite if he was that "con who destroyed that city". Underbite was pleased to hear that Grimlock recognized him but Grimlock was referring to the smell of Underbite. Underbite immediately destroyed the stasis pod Grimlock was trapped in, thus freeing Grimlock in the process. Underbite noticed Grimlock was gone and noticed through the forest was a scrapyard full of metal. He transforms to investigate it. When the Autobots discovered that Underbite had escaped to go to the scrapyard, where [[Denny Clay|Russell's dad]] was.

[[File:PilotPart2_Underbite_Grimlock_square_off.jpg|250px|thumb|right|Underbite and Grimlock fighting.]]
Underbite made his way to the scrapyard until he was ambushed by [[Grimlock]], who then proceeded to fight Underbite. While [[Denny Clay]] was oblivious to the pair fighting, Underbite suggested that they were both on the prison ship and that he merely desired to eat the "crunchy parts" of metal on Earth instead of devouring the whole planet. Grimlock disagreed and swung his tail at Underbite, though Underbite was able to catch Grimlock's tail and toss him. While Grimlock almost had the upper hand, Underbite was able to bite onto his arm and tossed him aside. Underbite snacked on a few of Denny Clay's Beaver statues for power but dropped one. As he picked it up to eat it, Strongarm shot at the piece he was about to eat and he chased after Bumblebee and Strongarm. After a short chase, Grimlock was able to stop it by jumping onto Underbite to deliver a few blows. However, Underbite was able to toss Grimlock again but this time Grimlock passed out for a few moments, leaving Underbite to devour most stuff in the scrapyard until he spots Crown City and transforms to go after it. Underbite was getting weaker as he was traveling in the woods and stated that all that organic stuff is making him lose strength. He asked a bird of how far he was from the bridge, but the bird just stared at him blankly. Underbite was able to get to the bridge but was immediately stopped by Bumblebee, tossed over by Grimlock and shot at by Strongarm, with Bumblebee zapping Underbite. The weapons that Strongarm and Bumblebee used malfunctioned, leaving them defenseless against Underbite. Grimlock and Denny Clay covered Strongarm and Bumblebee until Sideswipe and Russell arrived to lure Underbite away with some of Denny's beaver statues. They were able to lure Underbite near the edge of the quarry, where the team were trying to push Underbite over the edge. Unfortunately for them, Underbite managed to grab and eat a few of the beaver statues from Sideswipe's trailer thus giving him power to push everyone back. With everyone pushed aside, Underbite managed to grab Denny Clay in his pick up truck and began to crush the truck with Denny inside.
[[File:Underbite_defeated.jpg|250px|thumb|left|Underbite after being thrown into the quarry by [[Optimus Prime]].]]
As the Autobots watched in alarm, [[Optimus Prime]] grabbed onto Underbite and tossed the Decepticon into the quarry. Later on, Underbite remained unconscious and was placed in a stasis pod by the team.

In [[True Colors]], [[Minitron]] controlled Grimlock to take Underbite's stasis pod directly to [[Steeljaw (Decepticon)|Steeljaw]]. While the Autobots were able to free Grimlock from Minitron's control, Steeljaw made off with the stasis pod and freed Underbite from it.

In [[Sideways]], Underbite became an official member in Steeljaw's gang with Steeljaw, [[Thunderhoof]], [[Fracture]], [[Divebomb (Decepticon)|Divebomb]], [[Airazor]], and eventually [[Clampdown]]. Underbite was hanging out with his Decepticon comrades until Thunderhoof chased Clampdown, which the rest of the Decepticons started to follow them. Steeljaw and his gang caught up in a confrontation with the Autobot at a garbage area where Underbite faced against Grimlock. Underbite ate some metal to boast up his strength but Grimlock managed to make the Decepticon eat plastic which made Underbite feel nauseated and Grimlock cannon-balled onto Underbite's back. Steeljaw freed his gang from their cuffs and they returned to their hideout to officially welcome Clampdown into the gang.

In [[Lockout]], Underbite took part in an attempt to free the prisoners in the Autobots' scrapyard. After Steeljaw trapped the Autobots outside using subsonics, Underbite was given the task of guarding the prisoners, only for them to escape while he was eyeing 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 where Steeljaw enraged his anger at his comrades, forcing Underbite and the rest of his pack to flee.

In [[Battlegrounds, Part 1]], Underbite took part in capturing Sideswipe and Strongarm. Back at the Decepticon hideout, Underbite and Thunderhoof were puzzled when Steeljaw was talking with Megatronus but as they saw it, it looked like Steeljaw was talking to a wall. Later, Underbite also took part in building the machines to bring Megatronus to Earth, where he and Thunderhoof was tasked to fend off the Autobots. Underbite fought Drift and as Drift swiped at Underbite's face, the scar on Underbite's face suddenly healed. Underbite headbutted Drift and was soon blasted away with everyone that was near the machine when Optimus Prime came and destroyed it. Megatronus was able to step out of it and onto Earth.

In [[Battlegrounds, Part 2]] , Underbite recovered from the blast and soon took the Autobots out for Megatronus. Megatronus complimented them and revealed his plans, which ultimately showed he lied to them. When Steeljaw ordered his pack to fight Megatronus, Underbite was frighten along with Clampdown and Thunderhoof as they tried to escape. However, they were soon confronted by the Autobots and Underbite stated they had time to pulverize them. Underbite fought Grimlock and was soon incapacitated when Bumblebee was thrown into the air and crashed into Underbite as Grimlock provided assistance. Underbite was unconscious for the remainder of the battle and was captured along with Thunderhoof, Fracture, and Clampdown as they were placed in stasis pods in the scrapyard.