* DescendedCreator: Series creator Mo Willems voices the Angry Scientist.
* ExecutiveMeddling: Cartoon Network outright demanded that all of the jokes that required reading be accompanied by an off-screen voice reading it. Willems and co. only compromised by adding the little man who shows up during those gags, randomly saying that he likes reading and disappears.
* FridayNightDeathSlot: The show suffered this quite a lot throughout its run. The first nine episodes aired at a decent time on the "Cartoon Cartoon Friday's" block. However, the last four episodes of the first season were delayed several months to Sunday evenings for no given reason. The show was initially cancelled after its first season because of low ratings. However, it was at the last minute greenlit for a second season, which began airing with the same time slot. Inevitably, the ratings became even worse, and after the second season, the show was gone.
* KeepCirculatingTheTapes: There are no [=DVDs=], and the first season was taken off iTunes for reasons unknown to man. The only episode that has been officially released is the pilot, as a bonus on ''WesternAnimation/ThePowerpuffGirls'' VHS "Dream Scheme" and the ''Powerpuff'' DVD "Powerpuff Bluff". This ill treatment is surprising because back when the show first aired, it had the highest ever rated premiere for a Cartoon Network series. The entire series (all 26 episodes AND the pilot) are available on Dailymotion and other online video sites in their entirety.
* ProductionPosse: Mo Willems worked on ''Series/SesameStreet'' before making this show, and five actors who worked on ''Sesame Street'' did voices on ''Big City'': Stephanie D'Abruzzo, Joey Mazzarino, Fran Brill, Jerry Nelson and Ruth Buzzi.
* ScrewedByTheNetwork: The show had a very tumultuous run on Cartoon Network.
** The first seven episodes premiered with strong ratings between November 2000 and January 2001, though episodes 8 and 9 were held back into March. However, the last four episodes of the season never managed to air until the summer of 2001, on Sunday evenings. The series was initially cancelled after the first season ended on July 29, before being UnCancelled shortly afterwards thanks to popular demand; a second season was ordered in early September of 2001, and started airing on December 2 that year. The first four episodes aired that month in the same time slot as late season 1. However, the show went on yet another hiatus in January 2002, and the last nine episodes were burned out over the following months with a time slot of Sunday night at 7 PM, [[FridayNightDeathSlot when the target audience would not usually be watching TV]]. The show aired it's last episode on April 7, 2002; after it reran five days later, the show officially died out.
** According to an old Toonzone thread, a third season was planned to begin airing in 2003 and was briefly in production, however it was cancelled at the last minute when the channel greenlit ''WesternAnimation/CodenameKidsNextDoor'', which debuted on November 29, 2002. Reruns became sparse after 2003, basically slipping silently off the air and CN's website. For a couple of years after, the only way to see Sheep was on Boomerang, but that too didn't last for long. Only the first season was also briefly available on iTunes at one point in 2006, but was shortly pulled for whatever reason. It wasn't until 2012, more than ten years after the show officially ended, that Cartoon Network acknowledged it's existence again as part of their 20th anniversary celebrations. However, after the milestone, the show slipped back into obscurity. The show was also acknowledged in 2016, when Cartoon Network uploaded the theme song to its YouTube channel, along with multiple other shows.
* WhatCouldHaveBeen: The sheep-powered raygun was originally supposed to be used to take over Wisconsin, but Mo Willems decided it was funnier if there was no explicit purpose to imply "General Specific and Private Public aren't too bright."