[[folder:''Men in Black'']]
* EnforcedMethodActing: TommyLeeJones was not amused by the script he was given, so he ad-libbed a good deal of his dialogue. Look closely enough and you can see WillSmith trying to keep up, as expected of the fresh recruit. The resulting synergy is well over half the movie's charm.
* HeyItsThatGuy
** The "Edgar-Bug" from the first movie is [[FullMetalJacket Gomer Pyle]]/[[Series/LawAndOrderCriminalIntent Detective Goren]], and Jeebs is {{Monk}}.
** [[Series/TheAddamsFamily Lurch]] is an alien?!
** Laurel's morgue attendant is [[Series/ArrestedDevelopment Tobias Fünke]].
** Zed is [[Film/{{Dodgeball}} Patches O'Houlihan]] but only in the movies.
* ScienceMarchesOn: A minor one. When J heads to the morgue to retrieve a cat, he hilariously tries to convince Laurel that the cat is a witness in a murder investigation. Fast forward about ten years and advancements in forensic science mean that animals who 'witness' a murder can be checked for any forensic evidence the killer may have left behind.
* SimilarlyNamedWorks: There is another ''Men In Black'', which was a 1935 Film/TheThreeStooges short that was nominated for an Oscar.
* TechnologyMarchesOn: K shows J a small alien disc and says "They're going to replace [=CD=]s soon". At this point, it's doubtful. It was based on [[ProductPlacement Sony]]'s [=MiniDisc=], which did indeed fail to be the wave of the future. Also, J's introduction is him chasing down an alien on foot to arrest him. These days, the fleeing suspect probably would have been tazed, ending the chase rather quickly.
* ThrowItIn:
** The scene where the alien that Kay killed in the beginning of the film transformed was not originally planned. The creators added it in because they realized that most people would have sympathized with the alien had he died as is, and wanted to ensure no sympathy was to be gained for the alien prior to being killed.
** Will Smith's line "It just be rainin' black people in New York!" was improvised but so hilarious that they decided to leave it in.
** In fact, a lot of the lines in the original film were this. Creator/TommyLeeJones was famously dissatisfied with the script and so he took it upon himself to "fix" it by ad-libbing a good deal of his dialogue and one-liners, The result was Creator/WillSmith, not to be outdone, having to play along too. It was hilarious enough that Barry Sonnenfeld just didn't care and threw it ALL in. And the movie ended up being praised for its witty dialogue, in case you needed more proof how awesome Tommy Lee Jones is.
* WhatCouldHaveBeen
** Creator/BruceCampbell was the one originally in mind to play the exterminator, but he turned it down to appear in some TV movie that even some of his more hardcore fans haven't heard of.
** Creator/ClintEastwood was originally offered the part of Agent Kay, but declined.
** Among the options for the role of Jay was David Schwimmer of ''{{Friends}}'' fame. Imagine a Film/MenInBlack starring Creator/ClintEastwood and David Schwimmer.
** [[Film/BatmanForever Chris]] [[Film/BatmanAndRobin O'Donnell]] was the original choice for Jay. [[Series/NCISLosAngeles He does get another shot at being an agent, though.]] [[Film/BatmanForever So even after murdering his family, Two-Face still wants Robin to join the MIB?]]
** QuentinTarantino was originally the first choice for Director after the success of ''Film/ReservoirDogs.'' Tarantino turned down the offer, instead choosing to focus on the creation of ''Film/PulpFiction.''
** Originally, there were going to be ''two'' alien ships looming over the Earth, demanding the return of the galaxy: the Arquillian ship, and a Baltian ship (Rosenberg was originally a Baltian in the script). Edgar came to Earth to deliberately start a war between the two races, said to be negotiating peace, so he can feed off the resulting war. The initial volley is compared to two gunslingers using a giant rock as cover. Eventually, they decided the Baltians were not necessary to the plot, so some work was done in post-production (dubbing the aliens' conversation into "alienspeak", for one), and long story short, Rosenberg became an Arquillian.

[[folder:''Men in Black II'']]
* ActorAllusion
** Know that weird language J speaks in to the guy in the mail room? Well, the mailman is actually [[http://en.wikipedia.org/wiki/Biz_Markie Biz Markie]], and that "weird alien language" is actually [[http://en.wikipedia.org/wiki/Beatboxing beatboxing]].
** Let's not forget that Creator/PatrickWarburton played a not-too-bright agent who joined MIB because he wants to be a hero. His codename? [[TheTick "Agent T."]]
** A lot of mentions were made of Serleena's ravenous appetite. One scene shows her scarfing down a massive burger. At the time the film was released, Lara Flynn Boyle was in the tabloids a lot because of her emaciated appearance, with a lot of gossips claiming she was starving herself. Like most starlets facing similar accusations, Boyle deflected it by claiming she was actually a BigEater and just had a superfast metabolism.
* HeyItsThatGuy
** Creator/PatrickWarburton, also known as [[FamilyGuy Joe Swanson]] (or [[{{Seinfeld}} David Puddy]] or [[WesternAnimation/TheVentureBrothers Brock Samson]]) appears near the start of the second film as J's partner. Sonnenfeld intended Warburton as the man who became TheTick, and said agent was called T.
** [[SinCity Gail]] is [[spoiler:The Light Of Zartha]]?!
** [[ThePractice Helen Gamble]] as Serleena.
* TheOtherMarty: Creator/FamkeJanssen was originally cast as Serleena, and completed some scenes before dropping out due to a death in the family, with the role subsequently recast with Lara Flynn Boyle.
** Will Smith's line in the sequel when showing Kay the car: "It used to come with a black man, but it kept getting pulled over". Apparently they reused it so much that he soon became sick of it.
** In ''MIB II'', rapper Biz Markie was visiting Will Smith on the set and they were beatboxing to each other. Sonnenfeld saw this, loved it, put Markie in as an alien in the post office scene, and added the part where J speaks to him in his native language (which was really just their beatbox routine).
* WhatCouldHaveBeen:
** According to the book ''The Man Behind the Mask'', MichaelJackson would have appeared in the sequel for free...''if WillSmith were dropped from the film so he could be the protagonist''. He couldn't convince Sony's higher-ups that this was a good idea, hence the cameo instead.
** The sequel would've used the World Trade Center in some way, but then September 11th happened.
** Yeardley Smith, Halle Berry, and Jennifer Lopez originally auditioned for the part of Serleena.

[[folder:''Men in Black III'']]
* ActingForTwo: Jemaine Clement as both 2012 Boris and 1968 Boris.
* ActorAllusion
** Hinted at. J doesn't like being called a dumbass in some dialogue reminisicent of ''{{Hancock}}''.
** When J takes a little girl's chocolate milk, she mistakes him for "the president" (UsefulNotes/BarackObama). WillSmith has spoken of a desire to portray Obama in a biopic. Obama himself has said that if a biopic is made, Will Smith is his first-choice to star in it.
** Griffin's love of baseball. Michael Stuhlbarg's ''other'' best-known role, Arnold Rothstein of ''BoardwalkEmpire'', has quite a bit to do with the development of baseball in the US.
** An alien race that survives by going from planet to planet and exterminating the population [[Film/IndependenceDay sure sounds like another Will Smith movie.]]
** Keone Young also played a character named Wu in ''{{Series/Deadwood}}''.
** Young Agent K doesn't like losing his gun and keeps a backup, just like a certain [[Film/TheFugitive Federal marshal]].
* DawsonCasting:
** K is supposed to be 29 in 1969. He's played by Josh Brolin, who was 43 during the filming. J [[{{Lampshading}} lampshades]] this, looking incredulously at K and snarking "Got some city miles on ya, huh?"
** Inverted with Will Smith as Smith was born in 1968. We learn J was at least 4-5 in 1969, making J a few years older than Will Smith.
** Also inverted with O. Emma Thompson was born in 1959 and thus would have been ten in 1969. The younger version of O looks to be in her mid to late twenties and is played by Alice Eve who would have been 28 to 29 during filming.
* FakeBrit: In the third film, [[BigBad Boris the Animal]] is played by the New Zealand actor Jemaine Clement. He's technically an alien, but he speaks with a British accent reminiscent of {{Tim Curry}}.
* HeyItsThatGuy
** When K was younger, he was Film/JonahHe}. Kinda explains a lot.
** So [[NoCountryForOldMen Tom Bell and Llewellyn Moss]] are the same person? An interesting twist.
** [[Series/ArrestedDevelopment GOB]] is Agent Double A, [[spoiler:J's partner in the alternate timeline]] in the third movie.
** [[Film/HarryPotter Professor]] [[Creator/EmmaThompson Trelawney]] replaced Z at the head of the MIB.
*** Who better than NannyMcPhee to keep all those people in line?
*** And when she was young, she even worked for the Starfleet as [[StarTrekIntoDarkness Carol Marcus]].
** Boris the Animal is Jemaine from Music/FlightOfTheConchords.
** The MIB chief in '69 is Series/SledgeHammer! and was Kitridge, the boss of [[Film/MissionImpossible IMF]] back in the 90s.
** Creator/KeoneYoung as Mr. Wu.
** Andy Warhol is [[CloudyWithAChanceOfMeatballs Flint]], [[SaturdayNightLive Stefon, Herb Welch, Vinnie Verdecci, and a slew of others]].
** [[BoardwalkEmpire Arnold Rothstein]] is a wacky alien who can see the future? Well, that explains the gambling talent and the tendency toward the XanatosGambit.
* McLeaned / RoleEndingMisdemeanor: [[spoiler:Zed]] was killed off because [[spoiler:Rip Torn]] had been arrested for drunk driving. And broke into a bank with a loaded firearm. So, more like [[FromBadToWorse Role Ending Felony.]]
* ThrowItIn: The FunnyBackgroundEvent by one of the guards when J, K and Griffin are talking to the colonel.

[[folder:''The Cartoon Series'']]
* DawsonCasting: "The Back to School Syndrome" has J go undercover as a high school student.
* HeyItsThatVoice:
** L in the first three seasons was played by [[Series/StarTrekVoyager Jennifer "Kes" Lien]].
*** And in season four, she was played by [[ThePowerpuffGirls Ms. Bellum]].
** K in the last three seasons was also [[TransformersGenerationOne Grimlock]] and [[{{Duckman}} Cornfed]].
** Frank the Pug was played by Eddie Barth, better known to audiences as [[SupermanTheAnimatedSeries Detective Bowman]].
** Season 2 saw the addition of Creator/GreggBerger as the voice of Agent K, voice of [[GarfieldAndFriends Orson Pig]].
** The villain Quintoon was played by René Auberjonois, better known as [[Series/StarTrekDeepSpaceNine Odo]].
** Kay's alien love interest Aileen is [[Series/SabrinaTheTeenageWitch Aunt Zelda]].
** [[Creator/DavidWarner Alpha]] is [[WesternAnimation/BatmanTheAnimatedSeries Ra's Al Ghul]], [[{{Freakazoid}} The Lobe]] and [[WesternAnimation/TheGrimAdventuresOfBillyAndMandy Nergal]], among others.
** Zed is [[WesternAnimation/TheCritic Duke Phillips]] and the Sheriff from {{Squidbillies}}, but only on TheAnimatedSeries.
** Buzzard is [[WesternAnimation/BatmanBeyond Blight]].
** Jeebs in the animated series is Creator/BillyWest, except for a few times that Tony Shaloub reprises the role.
* TheOtherDarrin:
** K's voice actor is replaced after the first season. L gets a new voice actress for the final season.
** Almost none of the actors from the movie reprised their roles for the show. [[{{Monk}} Tony Shalhoub]] did reprise Jeebs in a few early episodes, but Creator/BillyWest did the voice for the remainder of the series.
* SuspiciouslySimilarSong: The theme for the cartoon series carries the first few beats of Will Smith's eponymous "Men In Black" as part of its main theme, but ditches the rest of the song in favor of a instrumental hip-hop composition.