Gremlins 2 was released in 1990, but was planned for a much earlier release. Joe Dante was initially hesitant as he felt Gremlins had already had the ending it needed and a sequel would simply be there for profit. Work continued without Dante until it became so grounded that they turned to him and gave him full control over the movie and even tripled the budget. He finally relented and made the movie.
The plot revolves around After the death of his owner Mr. Wing (Keye Luke), the mogwai Gizmo (voiced by Howie Mandel) becomes the guinea pig of mad scientists working at Clamp Enterprises, an automatic state-of-the-art office building in Manhattan, run by eccentric billionaire Daniel Clamp (John Glover). At the mercy of the chief researcher Dr. Catheter (Christopher Lee), Gizmo is rescued by his friend Billy Peltzer (Zach Galligan) and his fiancee Kate (Phoebe Cates), both of whom work at Clamp Enterprises. Clamp quickly befriends Billy upon being impressed by his skills in concept design, also sparking the interest of Billy's superior Marla Bloodstone (Haviland Morris). Gizmo is left in the office, where water spills on his head and spawns new mogwai, including Mohawk (voiced by Frank Welker), who then has Gizmo locked in the vents. They eat after midnight, turning into gremlins.
After Gizmo finds a way out of the vent, Mohawk tortures him while the other Gremlins cause the fire sprinklers to go off and spawn a Gremlin army that throws the building into chaos. Billy attempts to lure the Gremlins into the lobby, where sunlight will kill them; after Billy briefs Clamp on gremlin knowledge, he inspires Clamp to try to save the city; Clamp, realizing the good PR it will bring, escapes outside through a secret tunnel to cover the front of the building in a giant sheet depicting nighttime to trick the creatures. The Gremlins devour serums in the lab; one becomes the intelligent Brain Gremlin (Tony Randall), who plans to use a "genetic sunblock" serum to immunize the group to sunlight. Another Gremlin turns into a female, while a third becomes pure electricity and, after killing Dr. Catheter, is trapped in Clamp's answering machine by Billy. All the while "Grandpa Fred" (Robert Prosky) catches the chaos on camera with help from a Japanese tourist named Mr. Katsuji (Gedde Watanabe), broadcasting it to the world; he dreams of being a proper anchorman but only works at Clamp Enterprises as the host of a late night horror show.
Murray Futterman (Dick Miller), Billy's neighbor from Kingston Falls visiting New York City and still trying to recover from the trauma from the events of the first film, encounters a bat-hybrid Gremlin the Brain Gremlin used the serum on; he covers it with cement, effectively turning it into a gargoyle. Murray realizes that he is not crazy as everyone believed and that he has to help; when Clamp escapes the building using a secret route, Murray uses it to sneak inside the Clamp building to aid Billy. Billy and the chief of security Forster (Robert Picardo) team up, but Forster is stalked and sexually harassed by the female Gremlin who is attracted to him. Mohawk finishes torturing Gizmo and devours a spider serum, transforming into a monstrous half-Gremlin half-spider hybrid. He attacks Kate and Marla, but Gizmo (tired of being bullied, dressed up like Rambo) confronts Mohawk and kills him with an ignited bottle of white-out. Outside the building, a rainstorm frustrates Clamp's plan as the Gremlins gather in the building's foyer, singing "New York, New York" as they anticipate all the havoc they're planning to cause.
Billy formulates a second plan to kill the Gremlin army: having Mr. Futterman spray the army with water and then releasing the electrical Gremlin, electrocuting and killing all of the army including the Brain Gremlin. Clamp charges in with the police and press, but sees the battle is already over; although disappointed he could not take part in the heroism, he is so thrilled by the end result that he gives Billy, Katie, Fred and Marla promotions and hires Mr. Katsuji as a cameraman. Billy and Kate then return home and Gizmo stays with them for good. Forster (covered from head to toe in lipstick marks) calls Clamp, explaining he's trapped in a restroom with the female Gremlin (the only survivor of the army), and is dismayed when Clamp says it will take hours to rescue him as they clear the building. The female Gremlin's initial lust reveals itself as a far more intensely passionate love as she approaches Forster in a wedding dress. After much horror and discomfort, Forster eventually gives in.
When the movie was released, it received generally great critical praise, as it was a satire of sequels and didn't take itself too seriously. It was even considered by many to be superior to the original film. It outperformed it's peers in Predator 2, Child's Play 2 and Exorcist III.