Trevor is Marco's brother, being three months younger than him. He helps him, along with Joel Gonzales and James Johnson, sabotage Maureen McReary and Hector Wilson's date at Tommy's Café. Joel walks in desquised as a grown-up and makes sure that the two are in the café. He signals Giovanni Ancelotti, who signals Trevor to walk in the café. Trevor tells Marco the exact location of Maureen and Hector. Marco comes up from behind them and attacks them with a slingshot. The couple run away, and the four deliquents celebrate their victory of ruining their date.
However, Joel's little brother Jose Gonzales does not find ruining their date funny, so he calls Patrick McReary and tells him to come to the café. Packie, along with his friends, arrive at the café immediantly. Salvador Real, "San" Salvador Martinez, Eduardo Tena, and Claude attack them with their paintball rifles. However, Packie, the Salvadors, Eduardo, and Claude are captured by Joel and his friends.
Suddently, Francis, Gerry, Derrick, and Kate save the five by attacking the villains and tying them up together. Two police officers, Charlie Macias and Fred Miller, arrive at the scene and arrest the four deliquents. They are taken to nearby Portage County Juvenile Detention.
This was only the first appearance of Trevor; he continues to reappear in many future comics working with Marco, James, and Joel in their never-ending plan to take over Green Bay.
Trevor wears plain pants and shoes. He wears a v-neck shirt similar to Salvador Ventura's, but without stripes. To hide his identity, he wears a Vancouver Vultures football helment. However, after "Like Father, Like Sons (And Daughter)", he does not wear this anymore; instead he wears a hat similar to Marco's, but with a T for Trevor on it. He also has hair sticking out of the hat. As of Season 7, just like Marco, they have the Wisconsin Warriors on their shirts.
- Trevor could have been one of the football players that appeared in Sibling Rivalries: Salvador Real's Adventures and "The Big Trade-Off".
- He and Marco were revealed to be James's cousins in "The Amnesia Act of 2015".
- He appears to be the weakest of the team, and is constantly being shown to be teased by Joel because of it, which is shown in "Best Frenemies" and "Great Balls of Paint".
- In "Best Frenemies", he was shown to possibly have bladder issues as he continued to leave to go urinate when the villains are ready to defeat Packie.
- Sibling Rivalries Pre-Series
- Sibling Rivalries (Season 3)
- Like Father, Like Sons (And Daughter) (first appearance)
- Sibling Rivalries (Season 4)
- Sibling Rivalries (Season 5)
- Sibling Rivalries (Season 6)
- Sibling Rivalries (Season 7)
- Sibling Rivalries (Season 8)
- Season 9
Total Number of Series Appearances: 11