* {{Blooper}}: In the second episode of the Japanese version, the professor who explains plot points to the audience refers to Koon-no-Kami as Inari-no-Kami. The latter was [[WhatCouldHaveBeen his name early in the show's development.]] This line was eventually redubbed with the proper name.
* HeyItsThatGuy: Kenji Kawai, who composed the background music (BGM) for ''Manga/RanmaOneHalf'', the ''Manga/DeathNote'' films and lastly, ''Anime/MobileSuitGundam00'' composed the BGM for the original Japanese version of this show. Hearing this, you will never take [[Anime/MobileSuitGundam00 Gundam 00]] so seriously again.
* HeyItsThatVoice: In Japan, every major character in cast voiced someone from Anime/MobileSuitGundam ranging from minor roles to major roles. For the main 3 members, we have [[Anime/MobileFighterGGundam Sai Saichi]], [[Anime/MobileSuitGundamWing Quatre]] and [[ZetaGundam Henken]] voicing them.
** Later on, [[Creator/AiOrikasa Pururun]] and [[Creator/YukoMizutani Omitsu]] would reunite in ''Anime/TenchiMuyo'' as Ryoko and Mihoshi, respectively.
*** Pururun would also reunite with Yattarou as [[Manga/InuYasha Jakotsu and Inuyasha]].
*** The aforementioned [[Creator/KappeiYamaguchi Yattarou]] is also [[Anime/OnePiece Usopp]] [[note]]And that's no "lie"...[[/note]]
*** [[Creator/MariaKawamura Usa-Hime]] is [[Anime/MobileSuitZetaGundam Beltorchika Irma]], [[Anime/MobileSuitGundamCharsCounterattack Quess Paraya]], and [[LightNovel/{{Slayers}} Naga the White Serpent]].
*** [[Creator/KoichiYamadera Karamaru]] is [[Anime/CowboyBebop Spike Spiegel]], [[Anime/NeonGenesisEvangelion Ryoji Kaji]], and [[Anime/MobileSuitGundamCharsCounterattack Gyunei Guss]].
** In the Mexican Spanish dub:
*** Yattarou / Speedy is [[PowerRangers Billy/Blue Ranger]] and [[WesternAnimation/RockosModernLife Rocko]]
*** Pururun / Polly is [[Manga/RanmaOneHalf Kodachi Kuno]], PunkyBrewster and [[Franchise/StarWars Wicket]]
*** Otama / Francine is [[Manga/AhMyGoddess Skuld]] and [[Manga/DoctorSlump Arale Norimaki in the original series]]
*** Karamaru / Bad Bird is [[WesternAnimation/TeenageMutantNinjaTurtles1987 The Shredder]] ([[CastingGag Curiously enough]]) and [[SaintSeiya Cassius]]
*** Lord Koon / Big Cheese is [[Manga/RanmaOneHalf Principal Kuno]] and [[Franchise/StarWars C-3PO]]
*** Miss Omitsu / Lucille is [[Series/TheXFiles Dana Scully]] and [[WesternAnimation/TheAdventuresOfJimmyNeutronBoyGenius Emi Ogasawara]]
*** Master Wanko / Al Dente is [[Manga/DragonBall Frieza]] and [[VideoGame/{{Halo 3}} Sgt. Johnson]]
*** Gennari / Jerry Atric is [[WesternAnimation/TheSimpsons Moe]]
*** The Narrator is [[WesternAnimation/TheSimpsons Barney Gumble]] and [[Manga/RanmaOneHalf Soun Tendo]]
** The English cast can also be heard in shows like ''WesternAnimation/{{Arthur}}''[[note]]Where "Polly Esther" is Arthur's mom.[[/note]], ''WesternAnimation/SagwaTheChineseSiameseCat''[[note]]Where Polly and Speedy Cerviche are Sagwa's grandmother and her bat friend Fu-Fu[[/note]], and ''WesternAnimation/TrippingTheRift''.
* MissingEpisode: Two, actually. Although the episodes in question are {{Clip Show}}s.
* NamesTheSame: In August of 2014 Pizza Hut launched a [[https://pizzacat.pzh.jp/ "Pizza Cat"]] ad campaign in Japan. Both [[http://blogs.yahoo.co.jp/robototenko/39047028.html character designer Noritaka Suzuki]] and [[https://twitter.com/ENma_Dororon/status/501591097563291648 Yattarou's voice actor Kappei Yamaguchi]] amusingly noted that Pizza Hut itself was making the same joke they had made over 20 years earlier.
* PlayingAgainstType: Guido's Japanese voice actor Creator/JurotaKosugi is usually known for his deep, masculine voice. Sukashii is a rare instance of him using a much higher, younger-sounding voice.
* WhatCouldHaveBeen: If it hadn't been for licensing issues, these cool cats would've been in ''VideoGame/TatsunokoVsCapcom''.
** It was also recently revealed that there were tentative plans for a police-themed SequelSeries called "Kyattou Keisatsu Beranmee".
** Various preliminary names and titles were printed in magazines prior to the show's debut. Early names for Yattarou included "Bugmaru", "Hypermaru" and "Kagetora", and one early show title was "Mecha Neko Ninpou Chou Bugmaru" (roughly "Mecha Cat Ninjutsu Book Bugmaru").
** The show could have been translated faithfully [[note]]As faithful as dubs of anime made for syndication got in the early 90's, anyway[[/note]] if they had never lost the scripts.