I'd mention Freakazoid. As to why, look to Pinky, Elmyra and the Brain.
Same basic creative team, fresh new IP, new ideas, backing from Steven Spielberg... What could possibly go wrong?
What did go wrong is that Tom Ruegger initially conceived Freakazoid as a kind of reference to Jack Ryder's character, in Batman's canon. That is, a zany, off-the-wall and yet still dark antihero. Sort of a slightly toned down take on the Mask, from the Monhke/Arcudi comics. Seven Spielberg wasn't up for it because, well, you know how Spielberg is about kid stuff. No violence or innuendo, please!
So, as a result, the darker pilot was never aired, and we ended up with the show that got produced. Ruegger would later go on to comment that keeping the cray-cray going for more than one season was getting fairly daunting. Anyone who's seen Freakazoid could confirm this; the show feels like Pinky and the Brain, if Pinky was the lead. That means a steady stream of nonsense, an established continuity and plot that was very quickly vacated in favour of MORE insanity - to the point where the executives got burned out.
The show never received a proper ending, but word on the Web is that "Normadeus" is the production team's last and best effort on the project. They'd received an early warning and starting putting all their eggs in the one basket they had. Someone had just come out of a viewing of 1984's "Amadeus", and figured they might as well lampoon Milos Forman's movie with the Lobe as Salieri and the Freak as Mozart. Well, loosely speaking.
The entire show is covered in self-conscious ribs and references to the cutthroat executives at the WB who, apparently, cut off entire animation teams at the drop of a hat. Ruegger's team had awesome resources to work with, but a terrible workplace environment and a pretty toxic backlog. All that resentment, built up from Tiny Toons to Taz-Mania and Animaniacs, all the way through to Pinky, Elmyra and the Brain...
Yeah. There's a crapton of very mature ribs at the industry in Freakazoid, which is what makes it all the more precious. I'd mention Histeria, too. Same team, same cancellation pattern, same reasons. The bile that's hidden in the cracks of certain episodes is fairly worrying.