Steven Spielberg was the film's executive producer, with the screenplay written by Chris Columbus. The film stars Zach Galligan and Phoebe Cates, with Howie Mandel providing the voice of Gizmo. The actors had to work alongside numerous puppets, as puppetry was the main form of special effects used to portray Gizmo and the gremlins.
Gremlins was a commercial success and received positive feedback from critics. However, the film has also been heavily criticized for some of its more violent sequences. Critics alleged these scenes made the film inappropriate for younger audiences who could be admitted into theatres under its PG rating. In response to this and to similar complaints about other films, the Motion Picture Association of America (MPAA) reformed its rating system within two months of its release.
Rand names the creature "Gizmo" and brings him home to his son. Billy is a young man who has taken up a job at the bank to make ends meet for his parents, with whom he still lives. He has a dog called Barney whose mischievousness makes both him and Billy the target of harassment from Ruby Deagle, an elderly woman with much financial influence. Billy's coworker and love interest Kate Beringer is also a local bartender; she sees directly the misery in the town caused by Mrs. Deagle's business practices.
Billy is fascinated with Gizmo, who is highly intelligent, can hum a tune, and proves to be a very gentle and well-behaved creature. Unfortunately, Billy's friend, Pete Fountaine, accidentally spills water on Gizmo. This causes Gizmo to go into convulsions and instantly multiply, spawning five new mogwai in a process that appears painful to him. The new mogwai are much more aggressive than Gizmo. They are led by the Mogwai Stripe, who has a white mohawk-like hairstyle. Billy brings one to Pete's science teacher Roy Hanson, who aggravates the mogwai by sticking a needle in it for a blood test. Ignoring Billy's cautions, Roy leaves food out, which the mogwai promptly steals and eats after midnight.
Eventually, the rest of the new Mogwai trick Billy into feeding them after midnight by stopping his alarm clock. All the creatures, except Gizmo, who was wise enough not to accept the food, soon form cocoons. While Billy is at the bank, the cocoons hatch, and the Mogwai emerge, having transformed into gremlins, monsters having sharp teeth, claws and dark green reptilian skin. Billy travels to the school to find Roy, only to find him killed by the gremlin at the school. Billy is injured and races to call his mother to tell her to get out of the house. Billy's mother Lynn is now alone with the gremlins, and comes into conflict with them. She manages to kill three, using household tools improvised as weapons. While she is being strangled by the next gremlin, Billy arrives and saves her by decapitating it with an ornamental sword. The only remaining gremlin left in the house is Stripe, who escapes. Billy tracks him down to the local YMCA, but the creature escapes once more by jumping into a swimming pool. Well aware of what is about to happen, Billy flees as an incredible multiplication of gremlins occurs.
Billy then takes Gizmo to the police station, to try to warn the townsfolk. The policemen ignore them to investigate a series of bizzare accidents, which Billy insists are the work of the Gremlins. Meanwhile, Stripe and his gremlin army attack the town killing many people. Billy then rushes to Dorry's Tavern to rescue Kate, who has been bartending that night. The gremlins have taken over the tavern, behaving in an exceedingly vulgar fashion, and force Kate to serve them. She eventually discovers they are frightened by light when she attempts to light one's cigarette. She then knocks down several through flash photography, and is reunited with Billy. The two seek shelter in the bank while the gremlins wreak havoc upon Kingston Falls. Notably, the creatures kill Mrs. Deagle by launching her through a window, and nearly kill a married couple called the Futtermans by driving a snowplow through their door. In the bank Kate tells Billy the story of why she hates Christmas; When she was nine years old, her father died climbing down the chimney in a Santa Claus suit. When Billy, Kate, and Gizmo re-emerge, they find the gremlins are gone. Billy and Kate track them down to the local theatre, where they are all happily watching Snow White and the Seven Dwarfs. Billy manages to blow up the theatre; all the gremlins burn to death except Stripe, who had left briefly to get candy.
Billy pursues Stripe through a department store; Stripe escapes and reaches a water fountain. By this time it is morning; Gizmo, having escaped notice of the human characters, opens a window blind and exposes Stripe to sunlight, killing him.
At the end of the film, Mr. Wing returns to collect Gizmo to prevent any recurrence of trouble. Mr. Wing observes that while Western society is not ready to properly care for a mogwai, Billy may one day be ready.
Michael Winslow also claims to have done some of Stripe's lines. He is credited among the other voices of the gremlins, however during commentary both Howie Mandel and Steven Spielberg have said that Frank Welker performed most of Stripe's lines and sound effects.
Director Joe Dante is a great fan of classic films (especially horror films) and puts many references in his own movies. He also frequently casts the stars of classic horror films in small roles. Examples in this film include Dick Miller and Jackie Joseph (co-stars of the original The Little Shop of Horrors), Robby the Robot from Forbidden Planet, William Schallert of The Incredible Shrinking Man, Scott Brady of Journey to the Center of Time, prolific Western star Harry Carey, veteran Warner Brothers animator Chuck Jones and Kenneth Tobey, star of The Thing (From Another World).
The notion of gremlins was first conceived during World War II, when mechanical failures in aircraft were jokingly blamed on the small monsters. Gremlins entered popular culture as children's author Roald Dahl published a book called The Gremlins in 1943 based on the mischievous creatures. Dante had read The Gremlins and claimed this book was of some influence to his film. Dahl's story is referenced in the film when the character Mr. Futterman, played by Dick Miller, drunkenly warns Billy and Kate of foreign technology sabotaged by gremlins: "It's the same gremlins that brought down our planes in the big one... That's right, World War II."
Falling Hare, a Merrie Melodies cartoon short featuring Bugs Bunny and a gremlin, was released by Warner Bros., also in 1943. In 1983, Dante publicly distanced his work from earlier films. He explained, "Our gremlins are somewhat different—they're sort of green and they have big mouths and they smile a lot and they do incredibly, really nasty things to people and enjoy it all the while."
Spielberg chose Dante as his director because of Dante's experience with horror-comedy; Dante had directed The Howling (1981), though in the time between The Howling and the offer to film Gremlins, he had experienced a lull in his career. The film's producer was Michael Finnell, who had also worked on The Howling. Spielberg took the project to Warner Bros. and also produced it with his own company, Amblin Entertainment.
The film's script went through a few drafts before a shooting script was finalized. The first version was much darker. Scenes were cut portraying Billy's mother dying in her struggle with the gremlins, with her head thrown down the stairs when Billy arrives. Dante later explained the scene made the film darker than what the filmmakers wanted. There was a scene where the gremlins ate Billy's dog and a scene where the gremlins attacked a MacDonald's and ate the customers but didn't touch the burgers. Also, instead of Stripe being a mogwai who becomes a gremlin, there was no Stripe mogwai and Gizmo was supposed to turn into Stripe the gremlin. Spielberg overruled this plot element because he felt Gizmo was cute and audiences would want him to be present at all stages of the film.
There is a famous urban legend referenced in the film, in which Kate reveals in a speech that her father died on a Christmas when he dressed as Santa Claus but broke his neck while climbing down the family's chimney. It was rumored that Columbus had written the scene as drama, though the filmmakers and performers took it as dark comedy. This scene was always a part of the Gremlins story. In the film the speech was delivered while hiding in the bank. One early version of the script included the speech in a scene where the leading characters found a McDonald's restaurant after it had been attacked and the patrons eaten, but the hamburgers were untouched. Later, the filmed speech would be controversial, as studio executives insisted upon its removal. They felt it was too ambiguous as to whether it was supposed to be funny or sad. Dante stubbornly refused to take the scene out, saying it represented the film as a whole, which had a combination of horrific and comedic elements. Spielberg did not like the scene but, despite his creative control, he viewed Gremlins as Dante's project and left it in. A parody of this scene is featured in Gremlins 2: The New Batch.
In contrast to Galligan, many of the supporting actors and actresses were better known; many were longtime character actors. Veteran actor Glynn Turman portrayed the high school science teacher whose study of a mogwai leads to his death after it forms a cocoon. Dick Miller was yet another experienced actor on the set, playing a World War II veteran who first refers to the creatures as gremlins. With so many experienced actors on the set, Galligan had the opportunity to query them about their careers. Rand was played by Hoyt Axton, who was always the filmmakers' preferred choice for the role even though it was widely contested by other actors. Axton's experience included acting as the father in The Black Stallion (1979), and he was also a country music singer-songwriter. Because an introductory scene to Gremlins was cut, Axton's voice earned him the added role of the narrator to establish some context. Mr. Wing was played by Keye Luke, a renowned film actor. Although he was around 80 in reality and his character is very elderly, Luke's youthful appearance required make-up to cover.
Corey Feldman, whom up to this time had primarily been in commercials would play Pete Fountaine; establishing his early credentials as a child actor.
Polly Holliday, an actress best known for her role in Alice, played Mrs. Deagle. Dante considered the casting fortunate, as she was well-known and he considered her to be talented. Ironically, two other well-known actors, Fast Times' Judge Reinhold and character actor Edward Andrews, received roles that were significantly reduced after the film was edited. They played Billy's superiors at the bank.
A few marionettes were also used. Other effects required large mogwai faces and ears to be produced for close-ups, as the puppets were less capable of conveying emotion. Consequently, large props simulating food were needed for the close-ups in the scene in which the mogwai feast after midnight. An enlarged Gizmo puppet was also needed for the scene in which he multiplies. The new mogwai, who popped out of Gizmo's body as small, furry balls which then started to grow, were balloons and expanded as such. Walas had also created the exploding gremlin in the microwave by means of a balloon that was allowed to burst.
Howie Mandel provided the voice for Gizmo, and the prolific voice actor Frank Welker provided the voice for Stripe. It was Welker who suggested Mandel perform in Gremlins. The puppets' lines were mostly invented by the voice actors, based on cues from the physical actions of the puppets, which were filmed before the voice work. Mandel also chose the type of voice for Gizmo, which was baby-like, based on what had been done. Mandel explained, Gizmo was "cute and naive, so, you know, I got in touch with that... I couldn't envision going any other way or do something different with it. I didn't try a few different voices."
Songs heard in the film include "Gremlins... Mega-Madness" by Michael Sembello. This song is played while the gremlins party in the bar, and one break dances to it. The Peter Gabriel song "Out Out," produced in collaboration with Nile Rodgers, is also heard in the bar scene. Darlene Love's song "Christmas (Baby Please Come Home)" plays over the opening credits.
While some critics criticized the film's depictions of violence and greed – such as death scenes, Kate's speech, and the gremlins' gluttony – as lacking comic value, one scholar interpreted these instead as a satire of "some characteristics of Western civilization." The film may suggest that Westerners take too much satisfaction out of violence. Gremlins can also be interpreted as a statement against technology, in that some characters, like Billy's father, are over-dependent on it. Kirkpatrick Sale interpreted Gremlins as an anti-technology film in his book Rebels Against the Future. In contrast, Mr. Wing is shown having a strong distaste for television. One scholar suggested the film is meant to express a number of observations of society by having the gremlin characters shift in what they are meant to represent. At different times, they are depicted as teenagers, the wealthy establishment, or fans of Disney films. The film the gremlins had been watching in the theatre before Billy blew it up was Disney's Snow White and the Seven Dwarfs.
Another scholar drew a connection between the microwave scene and urban legends about pets dying in microwave ovens. He described the portrayal of this urban legend in the film as successful, but that meant it seemed terrible. This is indeed a scene that is thought of as being one of the film's most violent; even Ebert expressed some fear in his review that the film might encourage children to try similar things with their pets, and he urged parents not to let their children see the film. Notably, TV edits of the second film actually edit out most of the microwave scene, due to similar problems.
Gremlins has been criticized for more than its depictions of violence. One BBC critic wrote in 2000 that "The plot is thin and the pacing is askew." However, that critic also complimented the dark humour contrasted against the ideal Christmas setting. In 2002, another critic wrote that in hindsight Gremlins has "corny special effects" and that the film will likely appeal to children more so than to adults. He also said the acting was dull.
Gremlins was a commercial success. It was filmed on a budget of $11,000,000, making it more expensive than Spielberg had originally intended but still relatively cheap for 1984. The trailer introduced the film to audiences by briefly explaining that Billy receives a strange creature as a Christmas present, by going over the three rules, and then coming out with the fact that the creatures transform into terrible monsters. This trailer showed little of either the mogwai or the gremlins. Conversely, other advertisements concentrated on Gizmo, overlooked the gremlins and made the film look similar to Spielberg's earlier family film E.T. the Extra-Terrestrial (1982).
Afterwards, Gremlins was released into US theatres on June 8, 1984, the same day as Ivan Reitman's Ghostbusters. Gremlins ranked second, with $12.5 million in its first weekend, 1.1 million less than Ghostbusters. By the end of its American screenings on November 29, it had grossed $148,168,459 domestically. This made it the fourth highest-grossing film of the year, after Beverly Hills Cop, Ghostbusters and Indiana Jones and the Temple of Doom. In August it opened in Argentina and Spain, and in October it premiered in West Germany. Screenings began in Australia and much of the rest of Europe in December. As Gremlins had an international audience, different versions of the film were made to overcome cultural barriers. Mandel learned to speak his few intelligible lines, such as "Bright light!", in various languages such as German. Regional music and humor were also incorporated into foreign language versions. Dante credited this work for Gremlins' worldwide success. Many critics questioned the summer release date when the film takes place during the Christmas holiday season and thought it should have had a Christmas release instead.
Still, there had also been complaints among audiences about the violence. This was particularly true among people who had brought their children to see the film, many of whom walked out of the theatre before the film had ended. Dante admitted to reporters later, "So the idea of taking a 4-year-old to see Gremlins, thinking it's going to be a cuddly, funny animal movie and then seeing that it turns into a horror picture, I think people were upset... They felt like they had been sold something family friendly and it wasn't entirely family friendly."
The film became available to audiences again when brought back to theatres on August 30, 1985. This brought its gross up to $153,083,102. It was also released on video that year, and made $79,500,000 in rental stores. The film was released on DVD in 1997 and again in 1999. On August 20, 2002, a "special edition" DVD was released featuring cast and filmmakers' commentary and deleted scenes.