Cartoons in 2008; all three have spawned successful television programs as spin-offs, including The Fairly OddParents, Johnny Bravo, Dexter's Laboratory, Courage the Cowardly Dog, My Life as a Teenage Robot, The Powerpuff Girls, and Adventure Time—for most of which he has served as executive producer.

The shows included Genndy Tartakovsky's Dexter's Laboratory, David Feiss' Cow and Chicken and I Am Weasel, Van Partible's Johnny Bravo, John R. Dilworth's Courage the Cowardly Dog, and Craig McCracken's The Powerpuff Girls.

After starting Frederator Studios in 1997, Seibert brought together a group of investors in a failed attempt to save the troubled underground/alternative comics publisher Kitchen Sink Press.

[14] Seibert's production of the first season of Natasha Allegri's Bee and PuppyCat for his Cartoon Hangover streaming channel was the most backed animated project on Kickstarter for several years.

[15] Seibert stepped down from his position as CEO of Frederator in August 2020, though the company indicated that he would remain executive producer for current projects, including Bee & PuppyCat and Castlevania.

Along with their affiliated Indy Mogul, Barely Political, Channel Frederator and several other networks, the company's superdistribution allowed it to become among the most widely distributed video in the world, and to become YouTube's top professional content provider.

[26][27][28] In 2004, then-unknown web developer David Karp interned at Frederator Studios at its first New York City location, and built the company's first blogging platform.

[29] In 2007, Karp launched Tumblr from a rented desk at Frederator Studios' Park Avenue South offices, along with chief engineer Marco Arment.

Cartoon Hangover gained a much larger audience with the revival of Bravest Warriors by Pendleton Ward on November 8, 2012[36] which originally aired as a pilot on Fred Seibert's Random!

After a late 1970s stint with media promotion innovator Dale Pon at New York's WHN Radio,[44] Seibert began his work at Warner-Amex Satellite Entertainment in 1980,[8] original owner of Nickelodeon and The Movie Channel and would go on to launch MTV: Music Television on August 1, 1981.

[45] The promos and network identifications his team produced did not resemble anything TV had every seen before, focusing on an approach that subtly made a series of "promises" to viewers in the wildest and most creative ways possible.

[59] While at Columbia he co-founded his first company, Oblivion Records with partners Tom Pomposello[60] and Dick Pennington, releasing LPs by Mississippi Fred McDowell (Live in New York) and Joe Lee Wilson.

He received an American Institute of Graphic Arts (AIGA) Medal for lifetime exceptional achievements in 2000,[70] was inducted to the Animation Magazine Hall of Fame in 2017.

[71] In November 2023, the National Academy of Television Arts and Sciences (presenters of the Emmy Awards) announced his induction[72] into their "Gold Circle," defined as performing "...distinguished service within the industry, setting standards for achievement, mentoring, leadership, and professional accolades for 50...years, respectively.