|“||We're all gonna die||„|
|~ Rattrap's catchphrase|
Rattrap is a Maximal soldier/spy who served in the Beast Wars and the Spark War on Cybertron in Beast Machines and one of the few Maximals who survived all the way to the end. He took the form of a rat and is the smallest of the Maximals. In season 2, he became a transmetal and was given wheels and became sort of a rodent race car. In Beast Machines, he was a rat in a beast mode but had wheels for legs in robot mode and with the ability to harness into Cybertronian computers. Although he has argued with every one of his Maximal counterparts, he was close friends with all of them. Though a strong fighter, he always assumes the worst and in almost every episode, he says "We're all gonna die".
Rattrap was one of the original Maximals who crash landed on prehistoric Earth with Optimus Primal, Rhinox and Cheetor. He took the form of a rat and took the name "Rattrap". When Dinobot joined the Maximals, Rattrap immediately disapproved of it and from then on, he and Dinobot would just about argue in every episode, with Rattrap calling Dinobot 'chopper face' and him calling Rattrap 'rodent' or 'vermin'. As the smallest and lightest, Optimus and later in the season, Airazor would carry him. In "Chain of Command", a mysterious alien device brought Optimus into another dimension, but could still contact with the others and he recruited Rattrap as temporary leader which angered Dinobot. In "Double Jeopardy", Rattrap accidentally allowed the Predacons to take a stasis pod who would soon become Blackarachnia and Optimus accused Rattrap of being a Predacon spy. After a series of misunderstandings, Rattrap won his trust back. In the next episode, Blackarachnia rewired the Maximal base and Rattrap snuck inside to re-rewire it back to normal. An explosion occurred in the process and the Maximals believed Rattrap was dead. Rhinox said Rattrap was his best friend and an alive Rattrap was flattered to hear that.
In the two part special about the floating island, Optimus brought Rattrap with him to help Tigatron and Airazor in stopping Blackarachnia from destroying the world with the island. In "the Low Road", Dinobot and Rattrap's arguing led to a point where they had to work together. They had to find Tarantulas whose latest invention gave Rhinox a continuous Energon cold. The arguing along the way was worse than before but they did knock out Tarantulas. In part 1 of the season finale, Rattrap, Optimus and Airazor found an alien base and engaged in a non weapon fight with Waspinator. In part 2, he painfully watched Optimus sacrifice himself to stop the alien explosion.
Although Optimus prevented the alien's nuclear bomb from hitting Earth, the impact shook the Earth and its
power turned Rattrap, Cheetor, Megatron and Tarantulas into transmetals. Cheetor could now fly and Rattrap now had wheels. Even with the new upgrade, Rattrap was not strong enough to hold off Megatron and his army of Fuzors and transmetals. Fortunately, Rhinox brought Optimus back to life with a new upgrade and Silverbolt joined the team and the Beast Wars continued on. In "Maximal No More", Dinobot loses the golden disks to the Predacons again and his loyalty went into questioning, mainly to Rattrap. In "Code of Hero", Rattrap kept hitting Dinobot below the belt with insults and decided to no longer trust him. Dinobot set out to redeem himself and single-handedly defeated the Predacons in battle which cost him his life. Before dying, Rattrap forgave Dinobot and said he would miss him. Dinobot said the same. Rattrap had the others give a salute in honor for their fallen comrade. In "The Agenda" arc, Rattrap snuck into Ravage's ship and caused it to self-destruct. He and the others traveled to the ark and were about to be wiped off from the Earth.
After Blackarachnia stopped Megatron from wiping out the Maximals and Optimus became a Transmetal II, Rattrap still didn't trust her which ended up causing him to butt heads with Silverbolt. In "Changing of the Guard", he traveled to the underwater Axalon to salvage Sentinel in a small submarine. He ended up losing it to the Predacons after crashing into Depth Charge. For the remainder of the season, Depth Charge took Dinobot's place of arguing with Rattrap. The two were forced to work together in rescuing a human girl in "Go with the Flow". In the series finale, he survived the war and returned to Cybertron.
Rattrap lost his Transmetal properties and returned to his original rat form when he returned to Cybertron and was now hunted by Megatron and his Cybertronian army. The organic turned him and the other Maximals into new forms. He was a modified rat and was given wheels for legs in robot mode. Since he had to "believe" to transform, it took him a few episodes to do so. When he did, he could secretly access into Megatron's data to retrieve information. He was still a loud mouth like before, but a little more mature and showed more respect towards others.
In season 2, the Maximals acquired a new comrade: Botanica. Unlike them, she took the form of a plant and became sort of their scientist ally and considered herself a pacifist who chose not to fight. Her pacifistic attitude had her butt heads with Rattrap but he secretly had feelings for her. In the finale, when Cybertron returned to its organic state, Rattrap was brought back to normal and when Botanica was revived, he was very glad to see her and the two became boyfriend/girlfriend.
- Rattrap is one of the three original characters to survive the entire Beast Era alongside Cheetor and Waspinator.