Underbite is a Gorgonopsid-like Decepticon that can transform into a tank-like car form, he is the first Decepticon to appear in Transformers: Robots in Disguise and is overall the first Decepticon to be fought by Bumblebee and team.
Robots in Disguise
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 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 Russell's dad was.
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.
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. 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, 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.
- "Pilot (Part 1)" (Debut)
- "Pilot (Part 2)"
- "True Colors" (In Stasis)
- "Battlegrounds, Part 1"
- "Battlegrounds, Part 2"
- "Breathing Room" (Mentioned)
- "Prepare for Departure"
- "Prisoner Principles"
- "Something He Ate"
Underbite is a Chompazoid who devours any form of metal for energy. He loves to show off his muscles and frequently boasts about how he devoured Nuon City often. He apparently named his muscles "Thundercruncher" (right arm) and "Boltsmasher" (left arm), which he would kiss like most body builders do. Underbite sides with the Decepticons and also despises the Autobots, especially his rival Grimlock. He is shown to be rather short-tempered as he immediately reacted violently towards Grimlock for insulting him.
Two things rule the thought processes of Underbite: eating and bragging. This Decepticon Chompazoid is extraordinarily proud of his strength, which increases as he consumes more metal. To him, everything is a workout, all in the goal of pumping up and bulking out. He's even gone so far as to name his forearms "Thundercruncher" (right) and "Boltsmasher" (left). He kisses them. He claims to have devoured the entirety of Nuon City, a feat about which he brags endlessly. So proud is he that he reacts quite violently to anyone not aware of his reputation.
Powers and abilities
Despite being the first Decepticon to battle Bumblebee, Underbite is a strong Decepticon, he has a great deal of strength, being able to both fought and managed to beat up Grimlock, sending him flying, and overpowered 3 Autobots at the same time. However, he is shown to be weaker than certain large Cybetronians, like Optimus Prime, getting easily overpowered and thrown down the cliff by him. His primary ability is eating huge amount of metal, which is the source of his power, the more metal he eats, the stronger he becomes. However, this also leads to his weakness, if he doesn't eat for a short period of time, he will run out of energy and strength. In addition, he is shown to get weaker by eating plastic, as seen when Grimlock threw a chunk of plastic into his mouth. Physically, he has few equals, provided he's got a steady diet of metal to masticate. However, on mainly-organic worlds like Earth, his rampages can drain him of power quickly, leaving him weakened. His need to feed is so strong that he'll ignore threats in favor of chasing down a pick-me-up. He has massively powerful jaws and teeth which helps him eat metal. He seems to self heal from wounds or scars, which was revealed in Battlegrounds, Part 1 where Drift swiped at Underbite but the scar on Underbite's face vanished.
Underbite seem to regard Steeljaw as a stern and fearless leader. They would rarely interact with each other but they remain close allies. In Battlegrounds, Part 1, Steeljaw complimented Underbite for tossing a piece of metal at Windblade.
Thunderhoof is seen to hang with Underbite in most occasions. In Battlegrounds, Part 1, the pair managed to take down Sideswipe with no hesitation. When Steeljaw was talking with Megatronus, Thunderhoof and Underbite looked at each other as it seemed their leader was just talking to a wall (in their views).
Underbite and Fracture seem to interact rarely, though they remain allies. In Sideways, the pair were seen to hang when Steeljaw introduced Clampdown to their pack, which made both Underbite and Fracture suspicious of their new ally.
Underbite seemed very suspicious of Clampdown when Steeljaw introduced him to the pack.
Underbite seems to regard Grimlock as a foolish and dim Dinobot. In Pilot (Part 1), Grimlock recognized Underbite since he ate Nuon City. Grimlock made it clear that it was Underbite's smell and not his muscles that made Grimlock recognize him, which Underbite inadvertently free Grimlock out of his stasis pod. In Pilot (Part 2), Grimlock faced Underbite in his dino mode. They shared a short conversation about fighting each other, which Grimlock reasoned that he liked to pick on things his own size and that he does not think of Underbite as "travel bud" since they both arrived on Earth as prisoners of the Alchemor. They are seen to fight around a few times, which Underbite managed to get the upper hand. Grimlock witnessed as Underbite as tossed in the quarry by Optimus Prime and when Underbite was being placed in a stasis pod. However, when Minitron controlled Grimlock, he managed to take Underbite's stasis pod to Steeljaw. In Sideways, Grimlock faced Underbite once more, which he made Underbite eat a block of plastic that made Underbite nauseous and gave Grimlock the upper hand to defeat Underbite. In Battlegrounds, Part 2, Grimlock took on Underbite and managed to get him in a position that Bumblebee (who flew when Megatronus blasts Optimus and send Bumblebee flying) managed to knock him out.
Underbite and Strongarm are seen to fight in some occasions. In Pilot (Part 1) and in Pilot (Part 2), Underbite and Strongarm are seen to fight. In Lockout, Strongarm managed to defeat Underbite by using her Decepticon hunter to hit Underbite in the stomach region and blast him. In Battlegrounds, Part 1, Underbite offered to chase Strongarm into a trap set by Fracture's Mini-Cons, which worked.
Bumblebee prevented Underbite from entering Crown City so that the latter could devour everything that was made of metal. Underbite didn't care if he had to go through Bumblebee to regain his full strength, which led to Bumblebee's team taking Underbite to a quarry where Underbite was promptly thrown into by Optimus Prime (who manifested himself in physical form). When Steeljaw's pack took over the scrapyard, Underbite told the Autobots that they were not on the "guest list", which Bumblebee told Underbite that he had that backwards. In Battlegrounds, Part 2, when Bumblebee was knocked into the air as Megatronus blasted a shielded Optimus Prime, he told Grimlock "Cannonball" as Grimlock fought Underbite and positioned him to be hit by Bumblebee on impact.
- "Heard of me?" - Underbite in Pilot (Part 1).
- "You ever been to Nuon City?"
- "That's 'cause I ate it!"
- "Little more juice never hurt anyone."
- "Yeah, transforming into a car will make a huge difference. Hello! I ate a whole city!"
- "Come here!"
- "I know what you're thinking. Is that tall, dark and handsome really Underbite, devourer of Nuon City?"
- "Ah, my old stasis pod. Should give me a little boost."
- "Feeling the burn!"
- "Finally! What gave me away? The muscles?"
- "How's that smell, you little Huh? Where'd he go?"
- "Heading for hugeness."
- "You're from the prison ship too. I'm not gonna eat the whole planet. Just the crunchy parts. So why are you bothering me?"
- "Even though we aren't buds, have a nice rest of your trip."
- "- Or Dinobots ain't so smart."
- "Ooh, cute."
- "I was hoping to work in a, uh, one rep max. But you're the one who's gonna *throws Grimlock in the air* feel the burn!
- "Thundercruncher. Mwah! Boltsmasher. Mwah! Undefeated and still champion."
- "Oh, it's hard-body heaven."
- "All this organic trash. I'm losing my pump."
- "You! How far am I from the bridge?"
- "I need a little iron to get my full shred back, and I don't really care if I have to go through you to get it."
- "Just the pick-me-up I was looking for."
- "That's what I'm talking about!"
- "Who's the boss now, huh?"
- "Who's rough? Who's tough? Who's huge?" - Underbite before being thrown in the quarry by Optimus Prime in Pilot (Part 2).
- "You want a piece of this, Dinobot?" - Underbite to Grimlock in Sideways.
- "Oh, yeah! Tough, toned and talented! Get ready to say hello to Earth's moon, Dinobot."
- "Is that? Ugh! Is that plastic? Aw, I'm gonna be sick."
- "Sorry, Autobots, you ain't on the guest list." - Underbite to Bee's team in Lockout.
- "Yeah? Why don't you come over here and tell Thundercruncher and Boltsmasher all about it."
- "Hey, I'd love to stomp him too, but you know Steeljaw would want us to bring him back." - Underbite about capturing Sideswipe in Battlegrounds, Part 1.
- "Waste of a tasty chunk of steel if you ask me."
- "How 'bout we stay just long enough to pulverize you?" - Underbite before facing the Autobots in Battlegrounds, Part 2.
- Underbite remains the only Cybertronian in Steeljaw's Pack to retain his Cybertronian vehicle mode.
- Underbite's name might had been a reference to how his jaw is an under bite.
- He is voiced by Liam O'Brien who is known for his role as the English voice actor of Gaara from Naruto.
- He is based on an extinct prehistoric animal who looks like both a dog and a mammal,which is a Gorgonopsid.