Wareheim graduated from Methacton High School in Norristown, Pennsylvania and then later attended Temple University, where he met his comedy partner Tim Heidecker and produced his first film about dads, shot on the Jersey shore. Wareheim and Heidecker are the creators, writers, and stars of Tom Goes to the Mayor, a limited animation that was on the Adult Swim programming block on Cartoon Network. Wareheim and Heidecker had mailed copies of an early version of the show to comedian Bob Odenkirk, who agreed to take on the project as the executive producer of the series and sold it to Cartoon Network. Wareheim played "The Mayor", an official who always managed to destroy Tom's well-intentioned plans often along with the entire town as well.
Tim and Eric Awesome Show, Great Job!
The Tim and Eric name was solidly branded with the release of Tim and Eric Awesome Show, Great Job! which premiered on February 11, 2007. The show is a mix of "live action, sketch, animation, emotions, phone calls, love, etc." according to their website. The creators have described the show as the "nightmare version of television." On May 2, 2010 the "Man Milk" episode of "Tim and Eric Awesome Show, Great Job!" wrapped Season 5 of the show. Though this would be the last serial content for "Tim and Eric Awesome Show, Great Job!" there was an hour-long holiday program titled "Chrimbus Special" that gave fans a last glimpse at the TV program. It was the second show Eric both produced and starred in which aired during Cartoon Network's Adult Swim block.
Wareheim played in several Philadelphia area bands, including the new wave punk band Twelve Tone System, of which Tim Heidecker was also briefly a member. Wareheim briefly played backup guitar for the duo Adam and Justine in the 1990s. Wareheim was also the principal songwriter for The Science Of and had been a member of Elements of Need, I Am Heaven, and briefly with the Vampire-themed punk band Ink & Dagger. He currently is involved with the band Sola.
Eric made an appearance in Aqua Teen Hunger Force as the Germ-Master, along with Tim as a basketball.
Wareheim, along with Tim Heidecker, also directed the 2010 Super Bowl commercial, The Shuffle, for Boost Mobile and most recently a series of Old Spice commercials with actor Terry Crews.
They also made an appearance in an episode of The Simpsons as Amus Bruse and Fois Garth.
Wareheim and Heidecker appeared together as Debt Collectors on the Adult Swim special, The Young Persons Guide to History and have made guest appearances in the movie Let's Go to Prison, as well as the Scottish video game series VideoGaiden and a Version 2 episode of Mega64. Wareheim also played a recurring role in Michael Cera's and Clark Duke's Internet TV show Clark and Michael as Randy, the neighbor of the titular duo.
Using characters and skits from Awesome Show, Heidecker and Wareheim (via their Abso Lutely production company) created an online-only show called Tim and Eric Nite Live!, originally broadcast on the website SuperDeluxe.
In 2015, Wareheim co-starred as Arnold Baumheiser in the Netflix comedy series Master of None. He appeared in six episodes and also directed four episodes.