Marvin McFadden (Lee Norris) or, "Mouth", as he is known, is a young man who is very loyal to his friends. Mouth is often seen as a nerd by his peers although his kind, non-judgmental and caring personality makes him a well-liked person. Mouth met Lucas Scott (Chad Michael Murray) in elementary school and the two have remained friends ever since. Although he has no athletic ability, Mouth loves sports. Seeing this love of sports Lucas included Mouth in the group of boys who played basketball at the rivercourt. Mouth was quickly accepted into the group.

Mouth began broadcasting the Ravens basketball games when Lucas joined the team. He also started a website "ravenshoops.com" with his best friend Jimmy Edwards (Colin Fickes). On the web site they would offer commentary on all the games as well as player interviews.

In high school Mouth had a crush on the head cheerleader, Brooke Davis (Sophia Bush), although he was too shy at the time to tell her how he felt about her. Brooke saw Mouth as a brother and nothing more. This upset Mouth as he wanted a relationship with her. Mouth got drunk one evening and threw a brick through Brooke's windshield. Eventually he confessed to her that he was the one who did it and told her how he felt about her. Brooke told Mouth that she thought they could no longer be friends. When she ran for Student Council President, Mouth stepped up and showed his support for Brooke.

Mouth dated former Class President Erica Marsh (Katherine Bailess) as well as his fellow sports caster, sophomore Gigi Silveri (Kelsey Chow). He also developed a crush on Rachel Gatina (Danneel Harris) whom he kissed but never dated. After college Mouth took a Sports Announcers job at a local television station where he had a secret affair with his boss, Alice (Kelly Collins Lintz). He ended things with Alice when he met Millicent (Lisa Goldstein), who was working as Brooke's assistant.

When allegations about Nathan Scott (James Lafferty), Lucas' brother and Mouth's friend, caught the attention of the media, Mouth was given a choice to either run the story or lose his job. Being the person he was, Mouth put his friendship above his career.

Quotes:

"Have you ever had your heart-broken?"

"Because sometimes, you have to step outside of the person you've been, and remember the person you were meant to be. The person you wanted to be. The person you are."