Pibby, if it did become real, would've been a production nightmare - IIRC the OK KO guys had to go to every individual cartoon creator for approval for their crossover, and most of those characters were just statues. Like, imagine the process of:
- Find a willing consultant who worked on a series
- Find as many model sheets, background graphics, and reference materials as possible
- Research the show's history to make sure there's no associated real-world tragedies or character inspirations you could step on the toes of as a horror show
- Learn the individual animation styles and their quirks
- Watch as much of the show as you can to sort out the character personalities
- Apply those character personalities to a situation and tone they were not created to exist in
- Figure out a way to market this episode without drawing the attention of their original target demographic
- Do this EVERY WEEK.