- Acting for Two:
- Beam Me Up, Scotty!: Raphael never says "Cowabummer!" in response to Batman showing him the place where he watched his parents die, that is merely an edited image.
- Creator-Preferred Adaptation: James Tynion IV, who worked on the comic, gave high praise to the movie.
- Edited for Syndication: When the movie aired on Nicktoons Network, some scenes were altered or cut. The blood from some of the fight scenes were removed, and the scene where Ra's Al Ghul murdered a security guard still has his head intact. Somewhat surprisingly, the post-credits scene, which shows a Jokerized Shredder, was removed, and on the flip side, Leo's Scarecrow induced nightmare where he dreams of his brothers as rotting corpses was kept in.
- Executive Meddling: A minor example. According to this article, one of the things Nickelodeon specifically requested was to not have anyone from the current cartoon voice their characters. note
- Fan Nickname: Fans have taken to calling the Jokerized Shredder, "The Shredder Who Laughs".
- Milestone Celebration: Along with Batman/Teenage Mutant Ninja Turtles III, this film is being released during the 80th anniversary of the creation of Batman and the 35th anniversary of the TMNT's creation.
- The Other Darrin: A very odd example happens in the Latin American Spanish dub: Unlike with other recent crossover movies when one or many franchises were originally dubbed in another country (mainly Mexico), the entire film was dubbed in Venezuela, including the Turtles. While this is expected with Venezuelan dubs when characters from the DCAU are involved, traditionally almost all the animated, live-action and the few videogame adaptations of the TMNT franchise has been dubbed in Mexico with Mexican voice actors since day one since the 80s, being the only exception Teenage Mutant Ninja Turtles II: The Secret of the Ooze, who was dubbed very badly in Argentina in the 90s (and receiving a better received Mexican dub later on), being this film the first non-Mexican-dubbed TMNT film in basically decades.
- Promoted Fanboy: Put simply, Troy Baker was ecstatic at being part of this movie.
- Role Reprise: Many voice actors from previous DC and TMNT properties reprise their roles. They include:
- Troy Baker reprises his roles as Batman and Joker, respectively from the LEGO Batman video games and Batman: Arkham Series. Tara Strong follows suit as Ivy and Harley from the respective projects.
- From the Teenage Mutant Ninja Turtles short Turtles Take Time And Space, Eric Bauza and Darren Criss return as Leonardo and Raphael.
- From Batman: The Brave and the Bold, John DiMaggio returns as Mr. Freeze.
- From The Batman, Tom Kenny once again voices The Penguin.
- Carlos Alazraqui reprises his Justice League: Doom role as Bane.
- Brian George reprises his role as Alfred from Batman: The Killing Joke
- Jim Meskimen reprises his role as James Gordon from Batman: Gotham Knight
- In the French dub, Franck Lorrain, Julien Allouf, Adrien Larmande and Nathanel Alimi reprise their roles as Leonardo, Raphael, Michelangelo and Donatello from the dubs of the 2010's live-action films.
- Talking to Himself: Troy Baker as both Batman and the Joker; they even have a dialogue scene together! (He'd voiced one or the other in multiple past animated productions and games, but this is the first time he - or anyone else, for that matter - played both in one work.)
- Voices in One Room: Averted. At Wonder Con 2019, it was revealed that none of the actors recorded together.
- Write Who You Know: Marly Halpern Graser put some facets of his personality into Donatello, most notably his geeky side. The scenes where he and Batgirl interact are also laced with this.
Trivia / Batman vs. The Teenage Mutant Ninja Turtles