In Bigger! Badder! Brutal-er!, the Toxic Rats are formed after a race through the forest, according to the order the contestants cross the finish line. Lightning, Scott, Dawn, Dakota, B, Sam and Staci are those selected as members of the team. This team is considered one of the most dysfunctional teams in the series where most of its members are easily distracted or unhelpful at all. From the very first challenge, Staci spends more time talking about what her ancestors allegedly invented and Dakota is posing for her paparazzi. Ultimately, B comes up with a plan that almost succeed but due to misfortune, they lost the challenge despite coming in first place. For sprouting out nonsense non-stop, Staci is eliminated that night.
Behind everyone's back, Scott plans to find the McLean-Brand Chris Head in order to save himself while he plays the role of the saboteur for his own team. In Truth or Laser Shark, the Rats almost win the challenge but Dakota gets distracted by the presence of paparazzi again, allowing Cameron to win it for his team. Because of this, along with a premonition from Dawn, Dakota is eliminated that night. In Ice Ice Baby, Scott begins to target B, seeing his inventions a threat to his plan. He also plans to get rid of Dawn, finding her "skills" creepy. Near the end of the challenge, Scott notices B's giant mirror melting the Maggots's ice fort. Not wanting to win, Scott throws a snowball at the mirror, deflecting the sunlight to the Rats's fort instead, securing their defeat. Scott immediately blames B for sabotaging the team. He later tells everyone to vote him off, which they do, much to Scott's satisfaction.
In Finders Creepers, the Toxic Rats finally win their first challenge due to Sam's determination, much to Scott's frustration. Brick is transferred to the team as it was supposed to be a non-elimination round. His status as the "new guy" makes him unable to fit in with the other guys on the team in Backstabbers Ahoy!, especially Scott. He takes charge of the team and is responsible for them winning the first challenge. They however lose the second round after Scott knocks Sam out, claiming that it was Jo who shot him. However, Dawn immediately sees through his lies and vows that Scott will pay for his betrayal. Unbeknownst to her, Scott overheard her plan and frames her for stealing the other campers' belongings, which he was originally going to use for Brick. In Runaway Model, the remaining members dub themselves "Team Man" but Sam is treated as an outcast. They attempt to use Sasquatchanakwa as their model for the fashion challenge, by luring him onto the runway, while he is in a fit of rage and kidnaps Lindsay. Sam almost wins the challenge for the team but ran out of power at the last minute. Being deemed as their weakest link, Sam is eliminated that night. At the same time, Jo and Scott switch teams.
A power struggle between the remaining three members occur in A Mine Is a Terrible Thing to Waste, but in order to get rid of Brick once and for all, Jo pulls Lightning into an alliance. The Rats lose again after Brick decides to help his former team, desroying his gold statuette in the process. Because of this, he is eliminated that night. In The Treasure Island of Dr. McLean, the remaining two Rats struggle due to them being outnumbered, but Jo ultimately finds out where Gwen and Sam are and digs them out, ending the Rats' losing streak.
The teams are merged in Grand Chef Auto, with Lightning and Jo being the only members of the team remaining.
|Toxic Rats teammates|
|B | Brick | Dakota | Dawn | Jo | Lightning | Sam | Scott | Staci|
|Contestant||Gender||Rank||Team rank||Episode||Reason for elimination|
|Staci||Female||13th||7th||Bigger! Badder! Brutal-er!||Her constant comments about her relatives irritated her teammates.|
|Dakota||Female||Returns||Returns||Truth or Laser Shark||She costs the team the win by being too distracted with the paparazzi.|
|B||Male||12th||6th||Ice Ice Baby||Scott saw him as a threat, and sabotaged him to make it seem like he lost the challenge.|
|Dawn||Female||11th||5th||Backstabbers Ahoy!||She was accused of being a thief after Scott framed her for stealing from the other contestants.|
|Sam||Male||10th||4th||Runaway Model||He failed to win the challenge for his team, seeing the challenge as a video game.|
|Brick||Male||9th||3rd||A Mine Is a Terrible Thing to Waste||He was too assertive, and helped the other team with the mutant gophers.|
|Jo||Female||5th||2nd||Up, Up And Away In My Pitiful Balloon||Cameron and Lightning voted her off due to their dislike towards her.|
|Lightning||Male||1st/2nd||1st||Brain vs. Brawn: The Ultimate Showdown||He pinned Cameron down for three seconds in the final challenge, thus winning the million dollars; came in second in Cameron's ending.|
- The original team name for the Toxic Rats was the "Radioactive Rats." Christian Potenza confirmed that the name for the Radioactive Rats was scrapped on September 27, 2011 because of the nuclear disaster in Japan.
- This is also the first team in the series to have a name change for the finished product of a season.
- This is the first team in Total Drama history with a green-themed logo to be the weaker of the two teams in its season.
- This is one of four teams to, at one point, consist entirely of one gender before the merge. This, however, changes after Jo switches teams with Scott, reverting the team to both genders again.
- This team has the larger amount of members of the two teams in Total Drama: Revenge of the Island, as it started out with seven against the Maggots' six, and then gained two additional members.
- This team features the highest amount of members eliminated consecutively out of any other team in the series, as they lost six members in a row.