Early reboot designs by Studio MDHR, the studio behind Cuphead.
As is the case with the original show, there are a ton of rejected ideas for the reboot that didn't make the cut.
- The art style
of the revival was originally going more experimental, with producer Gabe Swarr seeking out various artists. From Studio MDHR (Cuphead) bringing their Fleischer Studios-inspired sensibilities, to Violaine Briat bringing cutesy doodle pastels. Ultimately, the show's look became directly inspired by TMS Entertainment's contributions to the original series, given a streamlined look by Genevieve Tsai. - There were initially plans in place to have Freakazoid! make a cameo at some point in Season 1, but they ended up being abandoned due to scheduling conflicts with his voice actor, Paul Rugg. Ironically, he eventually ended up appearing in a Teen Titans Go! episode that aired only 6 days prior to the reboot's premiere.
- Also ironically, almost a year later, Rugg posted on Twitter a tweet in a recording booth heavily implying that he was finally gonna be returning to the franchise in a future episode, who turned out to be The Clown from the segment "Clown and Out".
- Also ironically, almost a year later, Rugg posted on Twitter a tweet in a recording booth
- According to this interview, the other characters (including Slappy and Skippy) were actually considered to return in their corresponding segments at one point in development, but it was eventually decided to scrap the idea to instead create new characters that would be more relevant to the 2020's; to say that most of the fans weren't receptive of both this decision and its reason would be a huge understatement. Thankfully, this was averted to an extent, as Slappy came back on the last episode of the third season (which is also the last), probably because of fan demand.
- In addition to being insulted in Jay-Pac's rap, Elmyra was originally going to make a cameo. Jay-Pac is holding her and looking like he's holding a dirty diaper.
- Mr. Skullhead was going to make a cameo in the same segment as well.
- Mr. Skullhead
- Randy Rogel wrote a song called "It Don't Get Much Smaller Than That," a pseudo-inverse of "Yakko's Universe," and has performed it live in concert in 2019. It wasn't used at all on the show.
- "Happy Narfday" had a scene where Brain kisses Pinky, but it was cut due to them not wanting Brain to give Pinky affection this early in the series.
- Bugs Bunny was going to be in "Bun Control" but was removed as his cameo wouldn't work.
- Rita and Runt were also supposed to appear on a poster parodying the "Hang In There, Baby!" motivational poster.
- Rita and Runt were also supposed to appear
- According to Genevieve Tsai, there were a couple of guest stars that ultimately did not end up happening:
- Lin-Manuel Miranda was interested in having a part in the reboot, either in a song or role.
- They were also interested in bringing Bob Odenkirk to voice Josh Polar, being in fact inspired by his character Saul Goodman. For some reason, this didn't happen.
