While attending Beverly Hills High School Mike began his musical career with the band False Alarm. After the band split up in 1983, he met Eric Melvin and Erik Sandin and formed the original line-up of NOFX. He has also appeared as a guest-vocalist on a number of other bands’ tracks including “Peter Brady” on Screeching Weasel’s 1993 album, Anthem For A New Tomorrow. Other appearances include “Beware” by Randy, “Mr. Coffee” and “Lazy” by Lagwagon, and can be heard heckling and requesting “Free Bird” at the end of the Lunachicks song, “Missed It,” off their 1996 album, Pretty Ugly, which he also produced. He also appears as a guest vocalist on the Dropkick Murphys single “Going Out In Style“. Mike is the owner and founder of Fat Wreck Chords, one of the most successful independent labels in North America.
Mike recorded the Cokie The Clown EP with NOFX, playing Cokie on both the cover of the EP and the music video for the title-track, “Cokie the Clown“. In the video, Mike dresses as Cokie and puts white powder into his squirting flower, which in the song he describes as “my own special blend of ex, coke, and K”. Cokie then walks around Chicago squirting powder in pedestrians’ faces, as chronicled in the song itself. The video was shot during the punk music festival Riot Fest.
Fat Mike has made several appearances as Cokie the Clown, but one of his most memorable was at Emo’s, a popular nightclub in Austin on March 20, 2010 at the South By Southwest Festival. He recounted several graphic and disturbing stories about his life, and played several songs both previously released and unreleased. He also tricked several members of the audience into drinking tequila, before showing them a video of himself filling a partially full bottle of tequila to the top with urine to shocked reactions. The stunt was later revealed as a joke on NOFX’s website, which showed Fat Mike switching out the urine bottle for an untainted one before making audience members drink it. Mike has since been banned from Emo’s.
In 2015 Mike premiered a Broadway Musical titled Home Street Home which he co-wrote with Soma Snakeoil and Jeff Marx.
In 2019, Fat Mike released a solo album, in the character of Cokie the Clown, titled You’re Welcome. The album features Fat Mike as Cokie as well as Dizzy Reed (Guns N Roses) and Travis Barker (Blink 182)
Fat Mike founded the website Punkvoter.com in 2004 in an effort to mobilize the punk community to vote George W. Bush out of office in that year’s presidential election. He had never been very active in politics before then, admitting that he never even voted until 2000. However, he was driven into political activism because of Bush, whom he viewed as “the most ridiculous president in the history of presidents.”Punkvoter.com targeted 18-to-25-year-old punk fans and other disenfranchised young people and encouraged them to vote Bush out of office. At its peak, the site was getting 15 million hits a day and ultimately raised over $1 million.