* ActorAllusion:
** Ditto is not RobPaulsen's first role as [[WesternAnimation/{{Animaniacs}} a black-and-white wisecracking creature of indeterminate species.]]
** In one episode where Ben and Gwen get sucked into a video game, Grandpa Max tells them to [[VideoGame/MetalGearSolid2 turn the game console off.]]
*** One video on Youtube explicitly noted that, like his role as [[VideoGame/MetalGearSolid Colonel Roy Campbell]], he carries many, many secrets and often acts as mission control.
** Richard [=McGonagle=]'s no stranger to voicing [[WesternAnimation/StarWarsCloneWars four-armed aliens]].
* HeyItsThatVoice
** Creator/TaraStrong plays Ben Tennyson, Upgrade, Benwolf, and Buzzshock.
** Creator/SteveBlum portrays [[BigBad Vilgax]], [[PlayingWithFire Heatblast]], [[OurGhostsAreDifferent Ghostfreak/Zs'kayr]], as well as many, many other voices.
** Creator/PaulEiding is Max Tennyson.
** You know how Ben's this intergalactic hero? He had a good teacher, literally. Voiced by Creator/JenniferHale, aka [[VideoGame/MassEffect Shepard.]]
** Creator/KharyPayton and Creator/KariWahlgren are respectively Hex and his niece, Charmcaster.
** Before the [[TheOtherDarrin voice change]], Kevin Levin is [[Anime/DigimonAdventure Matt Ishida]]!
** Creator/JimWard is Wildvine, [=XLR8=], and Diamondhead.
** Creator/FredTatasciore is Ripjaws, Cannonbolt, Way Big, and Future Ben.
* The first live action movie, ''Race Against Time'' was directed by none other than [[BillAndTedsExcellentAdventure Bill S. Preston, Esquire]]!
* GodDoesNotOwnThisWorld: Man of Action Studios created the original ''{{Ben 10}}'' show. It has been repeatedly stated by them and others that they have nothing to do with [[Ben10AlienForce the]] [[Ben10UltimateAlien three]] [[Ben10Omniverse sequels]], as ''Ben 10'' is owned by Cartoon Network and those shows were given entirely different creative teams. Ironically, Cartoon Network has brought Man of Action back on for the ContinuityReboot.
* IKnewIt:
** In the first episode Max corrects Gwen that Ben had turned into an alien instead of a monster, leading fans to think he was involved with aliens sometime in his past, as it turns out he was part of a an intergalactic law-enforcement organization called the "Plumbers".
** Some guessed that Ghostfreak would turn evil when they found out the MonsterOfTheWeek was an Ectonurite in "Ghostfreaked Out", despite some sources saying that it was a completely separate Ectonurite. When the episode aired, the truth became apparent after a nightmare detailing Ghostfreak telling Ben to ''let him out of the watch'', and then subsequently escaping the watch after dealing with Zombozo's unemployed henchmen.
* PlayingAgainstType: Creator/RichardStevenHorvitz as Grey Matter. The little alien is certainly more subdued (and a heck of a lot smarter) than a few of Horvitz's [[WesternAnimation/TheAngryBeavers other]] [[WesternAnimation/InvaderZim well-known]] [[WesternAnimation/TheGrimAdventuresOfBillyAndMandy roles]].
* WordOfGod states that Humans (Homosapians) in the series actually have special powers all their own but it isn't as obvious as other species. They can interbreed with most other species, they are one of only a very select few who can us magic and manipulate mana, and they are the only species who have a form of Adaptability which makes them suited to live in various climates, terrains, and even outer dimensions with little to no effort.
* At the very end of the where the elves try to get Grandpa Max to be Santa, you'll notice that the three children who talk to the old man look familiar. Who are they? Why, none other than Konohamaru, Moegi, and Udon from Naruto!
* WhatCouldHaveBeen
** Originally, Ben would have transformed into HUMAN superheroes, with the show seeming to be more inspired by ''ComicBook/DialHForHero''.
** Ben's first design had him as a freckled redhead.
** Gwen was originally going to be a classmate and one of his best friends, and she appeared in earlier concept art with a long ponytail and a pink shirt. She was changed to be a cousin since they may have been unable to figure out a decent reason for her to be on the road trip otherwise. The classmate aspect of this is referenced in the WhatIf episode "Goodbye and Good Riddance", where they become classmates at the end of the episode in order to better combat villains that might attack their hometown.
** Cannonbolt was originally meant to be in the original set of 10 aliens, but was eventually dropped in favor of Diamondhead.
** "Inferno" was considered as a name for Heatblast. Amusingly, this name was used for the Polish and French dub.
** Benwolf went through [[http://tnperkins.deviantart.com/art/Path-of-Development-Benwolf-79542661 numerous designs]] before being finalized.
** [[http://tnperkins.deviantart.com/art/Path-of-Development-Upchuck-79154482 Several designs were considered for Upchuck]]; two of them ended up re-used for future aliens Spitter and Articguana, and two more became villains in "Ken 10."
** Eyeguy was initially rejected due to being seen as too creepy; only when ''Secret of the Omnitrix'' did the writers decide to use him in an alternate scene.