* ActorAllusion: Creator/YuriLowenthal voicing a character getting an alien that can [[TunnelKing dig through dirt with ease]]? [[Anime/TengenToppaGurrenLagann Nah, it's probably just a coincidence.]]
** Yuri's in a [[{{Paprika}} final instalment of a supernatural series, huh?]]
** Not to mention TaraPlatt voicing the actress who he enters into a relationship with[[note]]They're married in real life.[[/note]].
** Creator/GregCipes' and AshleyJohnson's characters not getting along with Creator/TaraStrong's character initially? It's [[WesternAnimation/TeenTitans Beast Boy, Terra, and Raven]] all over again.
** Creator/GregCipes' character [[spoiler:[[WesternAnimation/TeenTitans turning into a psychotic monster]]?]]
*** Not to mention Creator/YuriLowenthal's character failing to trust someone who has gone over to the side of evil. [[Manga/{{Naruto}} Of course, last time he was in that situation, he was on the other side of things.]]
** More of a Studio Allusion, but Gwen's cousin Sunny is a complete expy of [[WesternAnimation/TeenTitans Blackfire]], down to having a black-and-purple colour scheme and being voiced by Gwen's VA, AshleyJohnson (In ''Teen Titans'', Blackfire and Starfire shared a VA, HyndenWalch).
** This isn't the first time JohnDiMaggio has voiced an obsessed [[WesternAnimation/SymBionicTitan military]] [[XMenLegends man]].
** In "Ben 10,000 Returns", when Kevin notices the strange fighting styles of the multiverse Ben counterparts under Eon's control, he asks Ben, "Since when did you learn ninjutsu?" Guess who else Creator/YuriLowenthal voices besides Ben? [[Manga/{{Naruto}} Sasuke Uchiha]].
* AuthorExistenceFailure: DwayneMcDuffie had died partway through the series. Didn't prevent the show's continuation and eventual sequel series, though, and all 52 episodes for ''UA'' had already been fully planned out before his passing.....though, for some reason or other, many plot threads brought up were left completely unresolved by Episode 52 ([[AbortedArc the arcs centering around Elena, Charmcaster, and King Viktor being the most noteworthy]]) and now likely never will be due to Dwayne's passing.
* CastingGag: Actress Jennifer Nocturne, who wants to get into a relationship with Ben, is voiced by TaraPlatt, the real-life wife of Creator/YuriLowenthal.
* CreatorBacklash: If [[http://www.formspring.me/DerrickJWyatt/q/305578315308085773 this formspring]] is to be believed, the person who designed Aggregor is embarrassed about him.
* TheDanza: In Poland, Julia is played by Julia Kolakowska.
* FandomNod: "Y'know, after all the hype, the Alien X smoothie was a real disappointment. Kind of tastes like filler."
** Fourarms tells Captain Nemesis that [[TransformationNameAnnouncement shouting out his name]] is "[[HypocriticalHumor stupid]]."
** [[spoiler:10-year-old Ben]]'s reaction to Swampfire: "Plant guy? That's just a copy of Wildvine."
* HeyItsThatVoice: Creator/DeeBradleyBaker uses his [[WesternAnimation/AmericanDad Klaus]] voice for [=ChamAlien=] and Prisoner Number 775.
* TheOtherDarrin: Zombozo is now voiced by Creator/JohnDiMaggio, rather than John Kassir.
* PlayingAgainstType: As mentioned in TheOtherDarrin, John Dimaggio as Zombozo, in what almost seems like practice for [[WesternAnimation/BatmanUnderTheRedHood another role]].
* RecycledScript: The plot for "Inspector 13" seems fairly similar to the first series episode "Secrets", down to Ben's arm being at the risk of being cut off for his watch.
* TalkingToHimself: Bivalvan, P'andor, Ra'ad, and Andreas are all voiced by Creator/DeeBradleyBaker. Galapagus is the only one not voiced by Baker, and is instead voiced by {{John DiMaggio}}, though it could count when Galapagus talks to Aggregor.
* WordOfGod: Dwayne [=McDuffie=] had [[http://dwaynemcduffie.com.lamphost.net/forums/viewtopic.php?f=2&t=2104 started a new thread]] for ''Ultimate Alien'' and any remaining ''Alien Force'' questions… Up until [[AuthorExistenceFailure he died]], at least.
** The Forever Knights KILLED Pierce, probably planned on killing all those aliens waiting for supplies, and Ben needed to threaten to KillEmAll to make them leave. As in, actually say KILL. Even their appearances and weapons have become DarkerAndEdgier. And now, most likely Old George will wind up somehow involved with The Lucubra.