Creative types can be petty, and they tend to not be shy about taking their grievances public. That's why it's so common to find that creators have used their work to take thinly veiled shots at their enemies, even in cases where said enemies are their employers. For example ...
6 The Fantastic Four Cartoon Was So Bad The Comics Mocked It
Hey, remember that terrible adaptation of Fantastic Four? Sorry, we should be more specific. Remember that terrible adaptation of Fantastic Four from the '90s? Shit, that still doesn't narrow it down. OK, remember that terrible Fantastic Four cartoon that aired as part of the generically named Marvel Action Hour? If you don't, consider yourself lucky. It was bad. Really bad. "We half-suspect whatever God-forsaken sweatshop it was animated in also wrote and acted in it" bad. Even just listening to the intro music they stole from an '80s jazzercise video makes it clear how dumb it was:
The "Screw You":
Don't just take our word on its lack of quality -- Tom DeFalco thought it sucked, too. Don't recognize the name? He's one of the most influential comic book writers you've never heard of. He was even one of Marvel's longest serving editors-in-chief, a position we're told is important. He was writing Fantastic Four comics when the cartoon was on the air, and like everyone else over the age of 3, he thought it was the animated equivalent of a raccoon bite to the genitals. But you can't diss a show based on your own franchise, can you?
Well, not out loud. You can, however, have Ant-Man react in mock horror at the show's quality before laughing at The Thing as he turns away in shame.
This is presumably recreated in Ant-Man with scenes of the Fantastic Four movies.
Instead of quietly fuming and pouring himself a bottle of Jack every night like a good employee, DeFalco had Ant-Man stage an emergency to summon The Thing just so he could mock what a shoddy cash grab the cartoon was in the pages of the comic it was making money for. Look at Ant-Man's face in the bottom panels. Actual trolls that live under bridges and harass goats could learn a thing or two from him.
And speaking of biting the hand that feeds you ...
5 The Creator Of Invader Zim "Tortures" His Own Network
Jhonen Vasquez is best known as the creator of Invader Zim, a show about an alien incompetently trying to conquer the Earth that's beloved by hyperactive 13 year olds. Before that, he created the cult comic Johnny the Homicidal Maniac, which is pretty much exactly what you'd expect it to be.
Slave Labor Graphics
Someone, somewhere, saw this and decided he would be perfect for Nickelodeon.
Nickelodeon wanted Zim to target a slightly older audience, but presumably didn't familiarize themselves with Vasquez's work beyond "he does cartoons" and therefore failed to realize he would interpret that request slightly differently than them. To be fair, the show did feature people's eyes getting burned out, someone being killed via Looper-esque time travel and a demon made of ham, among much other insanity. But Vasquez still called working with Nickelodeon "absolute misery," "horrible," and "hell," and mocked the network for not getting the chaste show they wanted while having unrealistic expectations about working with him. Needless to say, he hasn't become a staple at the network.
The "Screw You":
To really stick it to the company that gave him his own television show and lots of money, Vasquez created a character named Nick. Nick wore an orange shirt with his own name on it, which happened to look exactly like Nickelodeon's logo.
Nick is used as a test subject by Zim to investigate human "happiness centers." Thanks to the giant probe shoved into his brain, Nick maintains a cheery smile no matter what suffering is inflicted on him.
Honestly, we could use one of those.
That's how Vasquez saw Nickelodeon -- always wanting to be happy and upbeat no matter what, as if the critical thinking part of their brains had been hijacked. If Vasquez had been given total creative control, Nick would have presumably been publicly decapitated with a rusty chainsaw and then had his body crucified in the town square as a warning.