- Actor Allusion: It's stated in the intro song that Randy is "Bruce". The Brazilian lyrics went further and said he's Bruce Lee.
- Jim Cummings was born and raised in New Orleans, so Catfish's accent isn't that much of an affectation.
- Creator Cameo: Jed Einoff and Scott Thomas, the creators, executive producers, writers, and additional voice actors of the show, appear in the show as teenage-version of themselves in the background throughout several episodes.
- Creators Odd Ball: To an extend. While creators Jed Elinoff & Scott Thomas have had prior animation work before RC9N as writers, all their work as producers and creators have been live-action programs such as Best Friends Whenever and Raven's Home.
- Fan Nickname:
- The Ninjanomicon, already having the canon nickname Nomicon, has been occasionally known as Nomi within the fandom, mostly associating with its Moe Anthropomorphic form (also courtesy of the fandom).
- The series itself has been called Ninjashow, Ninja Show, and other variations. Mostly, curious as it seems, when anticipating the next episode (i.e. I cant wait for more Ninjashow, I gotta have my weekly dose of Ninjashow, with the exception of Ive been catching up on some Ninjashow lately). In general, the Tumblr fandom almost never uses the full name of the show; the main tag is #rc9gn, and users will either refer to it as that or Ninjashow - even the production blog is just called 9th Grade Ninja.
- Evil Julian is often referred to as Ghoulian due to his white, ghostly color scheme.
- Name's the Same: This TV show is not about former NFL quarterback Randall Cunningham.
- The Other Darrin:
- Ben Cross takes over as The Sorcerer in season 2, replacing Tim Curry due to the latter's stroke.
- S. Ward Smith was played by John Witherspoon in his first appearance and by Gary Anthony Williams in season two.
- The Other Marty: According to this video that he made (go to 3:50), James Arnold Taylor was one of the original choices to voice Randy himself, and recorded dialogue for a few episodes before Ben Schwartz ended up in the role.
- Out of Order: There is a bit of it in the show.
- Viva El Nomicon chronologically should be before the Halloween Episodes, Dawn of the Driscoll and Night of the Living McFizzles, because that is when McFist bought Whoopee World.
- Ninja Camp was supposed to air immediately after Silent Punch, Deadly Punch, but Stank'd to the Future aired instead.
- Evil Spirit Week chronologically should be before Silent Punch, Deadly Punch because that is when Randy gained the ability of Ninja Rage.
- Living in Shooblivion showed Julian in the background. The episode was aired after Snow-Klahoma.
- Screwed by the Network: The latter half of season 2. Very little advertisement of new episodes from it despite the series being one of their more popular shows. The remaining episodes were burned off at different intervals until finally the show quietly ended despite ending on a cliffhanger. At the very least they wrapped up the Sorcerer and Nega-Julian plotlines before they finished.
- Schedule Slip
- What Could Have Been:
- Apparently Heidi was originally supposed to be a cheerleader, Norrisville was originally going to called Malchio Falls, and the villain would have been a witch that looked like Sarah Palin.
- As mentioned above, James Arnold Taylor was one of the original choices for Randy.
- The Wiki Rule: Randy Cunningham: 9th Grade Ninja Wiki.
Trivia / Randy Cunningham: 9th Grade Ninja