EXCLUSIVE: Seth MacFarlane is human! The A-list showrunner, who is juggling four series, a movie and a music career, has reached a mutual agreement with Fox, 20th Century Fox TV and Warner Bros. TV to put the high-profile reboot of The Flintstones on hold as his insane workload has not allowed him to give the project the needed attention. Reps for MacFarlane, the network and the studio confirmed the decision, declining further comment.

After two years of complex dealmaking between 20th TV, where MacFarlane is based, and WBTV, which has the rights to the classic Hanna-Barbera series, the new Flintstones was announced at Fox’s upfront presentation last May with a straight-to-series order to launch in 2013. MacFarlane had been the driver behind the project as for him it was a childhood dream-come-true — by his own admission, the very first cartoon character he drew at age 2 was Fred Flintstone. MacFarlane was to co-write The Flintstones reboot, a co-production between 20th TV and WBTV, with Dan Palladino (Gilmore Girls) and executive produce it with him and Kara Vallow (Family Guy). To meet the 2013 target premiere date, The Flintsones was supposed to start production last fall, something that proved impossible as MacFarlane had been hard at work on his feature directorial debut Ted, his three Fox animated shows and another series for the network, an updated version of Carl Sagan’s classic Cosmos. MacFarlane is still busy doing post-production on Ted, a live-action/CGI comedy, which he also co-wrote and is voicing the title character for. The Universal-distributed film, starring Mark Wahlberg, opens July 13. On the TV side, MacFarlane has Fox’s Family Guy, American Dan and The Cleveland Show, all of which have been renewed for next season. (In addition to serving as executive producer on all three, MacFarlane also voices characters on two, Family Guy and American Dad.) Additionally, MacFarlane is shepherding another long-time passion project, the new 13-part docu-series Cosmos: A Space-Time Odyssey, which is slated for a 2013 premiere.

And then there is MacFarlane’s music career. His debut studio album as a singer, Music is Better Than Words, was released last September and went on to earn Grammy nomination in the Best Traditional Pop Vocal Album category alongside such music heavyweights as Barbra Streisand, Tony Bennett and Harry Connick Jr. and Susan Boyle.