Mel Brooks didn't want people to know he was a producer for the film because, he thought people wouldn't take it seriously if they knew he was involved. When people did find out he decided to make the most of it by handing out deely boppers at the premiere.
The infamous cat-monkey scene where Brundlefly fuses a cat and the remaining baboon and then beats it to death with a lead pipe was cut following a Toronto screening. According to producer Stuart Cornfeld the audience felt that there was no turning back for Seth and they lost all sympathy for his plight, which caused the rest of the film to not play as well. In Cornfeld's own words: "If you beat an animal to death, even a monkey-cat, your audience is not gonna be interested in your problems anymore".
The first name mentioned in the end credits is Chris Walas, Inc. as the creator and designer of the fly. After a screening the audience cheered upon seeing this first credit. Producer Stuart Cornfeld turned to Walas and said, "You're getting the Oscar". Cornfeld's prediction came true when Walas did in fact win the Academy Award for Best Makeup. Walas claims that this was probably because his name was listed first.
After watching some of his early films, director Martin Scorsese asked to meet David Cronenberg. Upon meeting him, Scorsese said he looked like a Beverly Hills plastic surgeon. This inspired Cronenberg to give himself a cameo as a doctor.
The scene where Seth and Ronnie are having coffee at the restaurant and Seth is talking endlessly was only half scripted when production began. The remainder was written the night before the scene was going to be filmed, as Jeff Goldblum felt that he could add more to the character.
While working at Fox, it was Scott Rudin's suggestion to Stuart Cornfeld that they hire David Cronenberg as director. Cornfeld agreed and after Mel Brooks had written an eloquent letter to the bosses at Fox, they agreed. Cronenberg's asking salary at the time was US$750,000. Brooks, Cornfeld and Fox, countered with an offer of $1 million, which sealed the deal.
Scripted, but never filmed, was a segment meant to have followed the deleted monkey-cat scene: A homeless lady screams after interrupting Brundlefly as he feeds out of an open dumpster. Brundlefly seizes the bag lady and disintegrates her face with his vomit drop. Before he finishes feeding on the woman's corpse, Brundlefly's humanity emerges for a moment; just long enough to contemplate the horror of his sub-human existence.
Veronica tells Seth (Jeff Goldblum) that "Something went wrong." Ellie Sattler tells Ian Malcolm (Goldblum) the same thing in Jurassic Park (1993). Brundle and Malcolm are also both in the habit of wearing the same set of clothes every day.
Although his script was extensively rewritten, Charles Edward Pogue still receives onscreen credit for the screenplay. David Cronenberg demanded that Pogue receive credit claiming that he would have never known how to write the script if not for Pogue's version.
The inspiration for the design of the telepods came from the shape of the cylinder in director David Cronenberg's vintage Ducati motorcycle. Brundlefly's "vomit drop" was, in reality, made from honey, eggs, and milk.
Originally, David Cronenberg turned down the film because of scheduling conflicts with the shooting of Total Recall (1990) for Dino De Laurentiis. The producers then hired Robert Bierman; unfortunately, Bierman experienced a terrible family tragedy just prior to the beginning of production and decided he couldn't make such a dark film. At about the same time, Cronenberg realized that he and De Laurentis were not seeing eye to eye on Total Recall and backed out, leaving him free to direct this film. Bierman has since stated that he has never seen the film, as it brings back bad memories and he does not want his own vision of it compromised.
David Cronenberg noted on his DVD auto commentary that the baboons used in the film frightened him personally, as they are potentially dangerous, physically very strong and, as very intelligent and very wild animals, are highly unpredictable. However, Cronenberg believed due to his tall and muscular physique, the baboons behaved affectionate and deferential towards Jeff Goldblum, who had trained and worked-out in preparation for the role, making the scenes with them easy to film. Other films using baboons often have mixed success, such as during the filming of The Omen (1976), when Lee Remick had to be rescued from an overly-excited baboon during the zoo attack scene.
Seth's saying, "Drink deep, or taste not, the plasma spring", is a reference to a famous quote from Alexander Pope's "An Essay on Criticism". The full quote is: "A little learning is a dang'rous thing; drink deep, or taste not the Pierian Spring: Their shallow draughts intoxicate the brain, and drinking largely sobers us again."
Several sequences were filmed but cut from the final release, including: a sequence where Brundle sends a cat and the surviving baboon through the telepods, resulting in a mutated creature he beats to death with a pipe; a scene where Brundle climbs the outside of his building as an insect limb emerges from his side; and an alternate ending in which Veronica has another dream of her unborn child, this time as a baby with beautiful butterfly wings.
David Cronenberg met with some opposition when he announced that he wanted to cast Jeff Goldblum in the lead role. The executive at Fox who was supervising the project felt that Goldblum was not a bankable star, and Chris Walas felt that his face would be difficult to work with for the make-up effects. Both, however, deferred to Cronenberg's judgment. Cronenberg himself later had reservations when Goldblum suggested Geena Davis, his girlfriend at the time, for the other lead role, as he did not want to have to work with a real-life couple. Cronenberg was convinced after Davis's first reading that she was right for the role. Producer Stuart Cornfeld suggested that they audition more actresses saying that it's the "script that is brilliant". Cornfeld relented after "nobody else even claim close".
In the 1990s, Geena Davis was reportedly involved with an alternate sequel to "The Fly", to be directed by her then-husband, Renny Harlin, titled "Flies". The script was said to feature a story where Veronica does not die in childbirth, and instead gives birth to twin boys.
The Chris Walas, Inc. designers studied graphic books on disease as a starting point for their "Brundlefly" makeup/creature designs. The final "Brundlefly" creature is horribly deformed and asymmetrical. This reflects director David Cronenberg's idea that the creature shouldn't be a giant fly, but rather a literal fusion of a man and an insect that embodies elements of both.
Screenwriter Charles Edward Pogue wrote the first draft of the script. When David Cronenberg was hired as director, one condition was that he be able to rewrite the script to his satisfaction. Cronenberg substantially altered the characters (and their names), the dialogue, and much of the plot. However, key details from Pogue's script (the fusion of man and fly and details of the metamorphosis) were retained.
After bringing Veronica, a journalist, to his apartment, the first thing Seth does to impress her is play the piano. In real life, David Cronenberg's mother played the piano, while his father was a journalist.
Co-producer Kip Ohman was the person who originally had the idea of remaking the original film. He had recently landed Charles Edward Pogue as a client, and suggested that he should be the one to right it. They pitched the idea to Twentieth Century-Fox, who agreed to finance it. After reading Pogue's first draft, however, they rescinded the offer. Not only would they not finance the picture, they refused to relinquish the rights so that Ohman and Pogue could take it to another studio. Ohman finally convinced Fox to distribute the picture if they could get someone else to finance it. Ohman ultimately found producer Stuart Cornfeld, who had previously produced The Elephant Man (1980), and therefore knew Mel Brooks. Brooks agreed to allow Cornfeld to use Brooksfilms to produce the picture, but decided a new writer was needed. Pogue was therefore booted off the project, and Walon Green was hired in his place. It was decided that Green's draft was even worse than Pogue's, so he was fired and Pogue was re-hired. Pogue was ultimately booted off the project once again once David Cronenberg demanded to be able to re-write the script to his own satisfaction, as a condition of coming on board to direct. Cronenberg and Pogue didn't actually meet until after the film had come out. When they spoke, Cronenberg told him "apparently we made a hit movie together."
An opera in two acts based on the movie was produced for the stage in 2008. David Cronenberg served as director, Howard Shore composed the music and the lyrics were written by David Henry Hwang (with whom Cronenberg collaborated on M. Butterfly (1993).
The first bar and the last bar of music on the soundtrack is taken from the last bar of music from Puccini's tragic opera 'Madama Butterfly'. Perhaps a reference to the deleted dream sequence of the heroine giving birth to a butterfly.
Chris Walas had a meeting with his crew prior to production. He said they could do this film or Gremlins 2: The New Batch (1990). Working on this film meant that they would have to come up with all of the designs and begin construction in three months. Walas' crew unanimously agreed that it wasn't possible in that time frame but decided to do anyway because it was more of a challenge.
An early treatment for a sequel, written by Tim Lucas, involved Veronica Quaife dealing with the evils of the Bartok company. Brundle's consciousness had somehow survived within the Telepod computer, and the Bartok scientists had enslaved him and were using him to develop the system for cloning purposes. Brundle becomes able to communicate with Veronica through the computer, and he eventually takes control of the Bartok complex's security systems to gruesomely attack the villains. Eventually, Veronica frees Brundle by conspiring with him to reintegrate a non-contaminated version of his original body. Cronenberg endorsed the concept at the time. Geena Davis was open to doing a sequel (and only pulled out of "The Fly II" because her character was to be killed off in the opening scene), while Goldblum was not (although he was okay with the cameo), and this treatment reflects that. However, a later treatment written by Jim and Ken Wheat was used as the basis for the final script, written by Frank Darabont. Mick Garris also wrote a treatment, with elements incorporated into the final film.
During his audition, John Getz recalls having a terrible migraine the entire time. Later, while filming Stathis' first scene where he and Veronica (Geena Davis) discuss the tape, David Cronenberg asked if he could have the headache again. This is why Getz has his fingers on his head throughout much of the scene (especially during the line, "He's conning you.")
The trivia items below may give away important plot points.
Geena Davis claims that the only time she felt "grossed out" by the amount of gore was in the scene where Seth's ear falls off and she holds him. She states that her reaction to holding her face up to Goldblum's was not acting and that she was indeed really grossed out.
Two puppeteers (one of them Chris Walas) were located underneath the floor animating the inside-out baboon while a third pumped blood. All three of them had to wear raincoats because of the large amounts of blood being pumped. Frequently the rest of the crew would break for lunch and forget about the three underneath the floor.
Stathis's melting hand was effect was created by sculpting the mutilated hand, then building up an intact hand on top of it out of gelatin. The gelatin was then melted using stage lights and a hair dryer, and filmed at low speed. Chris Walas essentially recreated the same effect he had used earlier for Toht's melting face in Raiders of the Lost Ark (1981).
Several versions of a happier ending were shot but ultimately never used. Two were filmed in which Veronica has another dream of her unborn child, this time as a baby with beautiful butterfly wings. She wakes up in both and is revealed to still be pregnant in one while her pregnancy is left open in the other. Another two versions featured her having an unseen nightmare and being comforted by Stathis, who in one version states the baby is his and in the other that it is dead. Jeff Goldblum admits to being angry about the filmed "Stathis" endings, as he felt Veronica ending up with Stathis undermined the tragedy of the film. Eventually it was decided that, although some of the filmmakers - including producer Stuart Cornfeld - liked the alternate ending, it was more appropriate to end with Seth's death as, according to Cornfeld, "Once your hero is dead your movie is over".
While filming the finale, the puppeteers under the floor would get bored and start gluing pictures to John Getz's real foot, or place it in oatmeal. Getz fondly recalls that he should have realized, being unable to move, that he was a perfect target.
The scene in which Seth breaks Marky's arm in the bar almost didn't happen. Chris Walas and his crew kept putting development of the effect on hold to focus on more difficult ones. The prosthetic arm piece and bone was made within a matter of days as soon as they realized they were almost out of time.
Chris Walas wanted to avoid the use of bladders for the final transformation in which Brundlefly becomes the "Spacebug" as the technique, created by makeup legend Dick Smith, had been used in films like An American Werewolf in London (1981) and The Howling (1981) so much that "housewives knew about it". He eventually came up with having the Spacebug's head extend and push the prosthetic likeness of Jeff Goldblum's head apart. Walas' crew constructed a puppet that featured a retracting and extending head.
John Getz claimed to have kept one of the prosthetic feet used in the film for years in his freezer with neighborhood kids visiting almost daily to see it. Another of the feet was turned into the base of a lamp and put in the Chris Walas, Inc. shop before going to Bob Burns' collection.