Celebrity Voice Actor: In the European French dub, Batgirl is voiced by vlogger Nathalie "Natoo" Odzierejko, while Robin is voiced by Danse avec les stars winner Rayane Bensetti, professional football players Antoine Griezmann and Blaise Matuidi voice Superman and the Flash respectively, and journalist and radio/television host Stéphane Bern voices Alfred.
Cowboy BeBop at His Computer: At one point, the Joker describes the Daleks as "British robots". Daleks are actually genetically-engineered creatures inside a battle tank, not robots. This is probably intentional, given that the aforementioned is a lot to get into in a single sentence and the Joker says to "ask your nerd friends" about them as an aside.
Development Gag: Carried over from another work with Billy Dee Williams as Two-Face. He never got to play the role in the Batman film series, as while he played Harvey Dent in Batman, Tommy Lee Jones took over as Two-Face in Batman Forever.
There's a long-running fandom joke: Robin exists to be a bright target to draw fire from the bad guys. In this film, Batman initially plans to use him as a disposable tool.
The Daleks aren't voiced by Nicholas Briggs, who voiced them in LEGO Dimensions and has been their official voice since 2005. Some archived recordings of Briggs are used, though.
Despite being in the main cast as Alfred, Ralph Fiennes doesn't voice Voldemort. Word of God is that they considered it, but it then would have been pretty much mandatory to contrive a scene where Alfred and Voldemort have a conversation, and it didn't seem worth the effort.
In the Japanese dub of the trailers, Robin was voiced by Takashi Onozuka, who is the dub voice of Robin in manyof theanimated adaptations when he appears, but in the film itself he's voiced the the comedian Yoshio Kojima instead. Also, Takehito Koyasu replaces Keiji Fujiwara as the regular dub voice of the Joker since the dub of Suicide Squad.
The Latin American dub is a special case: Unlike with other animated adaptations involving Batman or the DCAU, this is one of the few who wasn't dubbed in Venezuelanote Partly because this is a spinoff from another movie, which was dubbed in Mexico previously, and also because Mexican laws forbids dubbed films in theaters with non-Mexican dubs, albeit this is not always enforced. Keep in mind other Lego's animated films involving Batman were dubbed in Venezuela, but dubbed in Mexico instead. This become even more bizarre because there's another dubbed version used exclusively in Colombia, but only Batman and the Joker were dubbed by Colombian voice actors. The rest of the cast are still voiced by Mexicans.
In a much straighter example of this, none of the voice actors from the Latin American dub from previous film reprised their roles here, albeit many of them reprised their roles from their respective live-action films they appeared previously.
Michael Cera, after more than a decade of being mocked for every single performance being the same twitchy, stammering loser, is almost unrecognizable as Robin.
Kate Micucci as Clayface, an adult male villain as opposed to the young, heroic female characters she usually voices.
Alfred is probably Ralph Fiennes' first truly heroic role after a lifetime of playing villains and anti heros.
Billy Dee Williams returns to voice Two-Face after having previously portrayed Harvey Dent in the 1989 Batman movie.
Ever since Zach Galifianakis was announced as the Joker, Latin American dubbing fans reasoned that José Antonio Macías, the recurring voice of Galifanakis, would reprise the Joker (as in The Dark Knight and Suicide Squad). They were right.
The same goes in the Japanese dub, as Takehito Koyasu reprises his role as the Joker from the dub of Suicide Squad. Also, in a very bizarre twist on this, Kōichi Yamadera (Batman) reprise that role from both the Japanese dubs of the previous movie he appeared and also from the 1989 Batman film, which was broadcasted by TV Asahi in the 90s. In the same way, Hikaru Hanada, the regular voice actor for Superman in the dub of Superman: The Animated Series, also reprises that role in the movie, and being the only Japanese VA from the dubs of the DCAU who reprise his previous role here.
In the Canadian French dub, besides Daniel Picard reprising his role as Batman from Batman & Robin (much like in The LEGO Movie), there is also Commissioner James Gordon being voiced by Marc Bellier, reprising his role from The Dark Knight Trilogy, while Harley Quinn is voiced by Catherine Brunet, reprising her role from Suicide Squad. Regarding non-DC Comics characters, Voldemort is voiced by Jean-Luc Montminy, reprising his role from the Harry Potter movies.
Averted with Ralph Fiennes, who is in the movie, but as Alfred, not Voldemort.
Concept art shows drastically different designs that were considered for some of the characters, including a hipster-esque Riddler, a literal Robin Hood outfit for Robin, and a Tommy Lee Jones version of Two-Face.
The Nightwing outfit Dick dons during the final battle was originally much closer to the suit from the comics, even including the classic bird emblem.
Batgirl, Commissioner Gordon, Catwoman, and Two-Face were all intended to be white at various points in the film's development.
Some concept art has also revealed villains that didn't make into the final cut, including the Ventriloquist, Hush, Doctor Double X, and Silver Banshee.
Had Ralph Fiennes voiced Voldemort's cameo here, he would have gotten a scene with Alfred to play off the fact that they were voiced by the same man.
One of the intended villains to appear in the Phantom Zone was Darth Vader, but this was scrapped due to obvious copyright issues. Word of God confirmed he managed to escape on his own.
Plans for a sequel were in the works, but the underperformance of The LEGO Movie 2 led to Warner Bros. shelving all future LEGO movie projects. It was presumed to have died with the franchise when Warner Bros. ended their film production deal with The LEGO Group later that year, and it was later confirmed in 2021 to have been cancelled.
Other Trivia
A sharp ear might recognize that both members of Garfunkel and Oates are in this movie; with Riki Lindhome as Poison Ivy & The Wicked Witch of the West and Kate Micucci as Clayface.