Near Prosperity, Arizona, a truck accidentally dumps a barrel of toxic waste in a reservoir. A week later, an exotic-spider farmer named Joshua Taft (Tom Noonan) shows his collection to a boy named Mike Parker (Scott Terra), including an enormous Orb Weaver from Brazil. Later, Joshua is bitten by a tarantula and knocks over the spider cages. He and his parrot are devoured.
The next week, Chris McCormack (David Arquette) protests against Mayor Wade’s (Leon Rippy) proposition to sell the mine the former’s father owned. Chris is interested in Sheriff Samantha Parker (Kari Muhrer). At the mall, Mayor Wade says Chris’s father was delusional about gold in the mine. Mike finds Joshua and the spiders missing and the farm covered in webs. He tells Chris the spiders are enormous, but Chris doesn’t believe him.
Spiders show up everywhere through the mine tunnels beneath the town. Eccentric Harlan Griffiths (Doug E. Doug) broadcasts his theory about extraterrestrials. Ashley (Scarlett Johansson), daughter of Sheriff Sam Parker, breaks up with Bret (Matt Czuchry), and his motorcycle group is chased by giant spiders. Bret is the only survivor. Chris’s Aunt Gladys (Eileen Ryan) and her dog are abducted by a male Orb Weaver, and Asley and Chris are attacked. Samantha kills it with a shotgun and tells Deputy Pete Willis (Rick Overton) to gather all the guns at the station.
Sam broadcasts the truth over the radio and a giant tarantula attacks the truck, though those inside escape. The whole town is attacked and many are eaten. They barricade themselves in the mall. Harlan and Chris climb up on the roof and climb the radio mast, trying to alert the military. They think it’s a prank. Harlan jumps from the roof and finds Pete in the bushes as the tarantula breaks open the gates and the spiders pour into the mall.
Bret arrives on a forklift, knocks down the gate and they enter the methane-filled mine tunnels. Chris finds his Aunt Gladys and the gold that no-one else believed was there. They are cornered by the giant Orb Weaver named Consuela. Distracting the spiders with perfume, Chris escapes on Bret’s motorcycle, blows up the mine and the spiders by igniting the methane gas. The town decides to cover up the entire incident, though letting Harlan broadcast the truth because nobody believes him anyway, and Chris re-opens the mine.
The film, originally called Arach Attack until the attack on Iraq, was produced by Roland Emmerich and directed by Ellory Elkayem, based on his 1997 short film Larger Than Life, written by the director, Randy Knowles, and Jesse Alexander. Eight-Legged Freaks was an actor’s ad-lib and they used it for the title. The spider army consists of the Orb-Weaver Consuela, Matriarch of the Spider Army, a second-in-command Giant Tarantula, a Pinktoe Tarantula, a Chilean Red Tarantula, a Mexican Redknee Tarantula, a Pink Foot Goliath, a Trapdoor Spider, an Australian Funnel-Web Spider, and a Spitting Spider.
It was shot in forty days, but the special effects had been worked on for seven months. It cost 70 million, ten of that for special effects. A cat fights a spider with kung-fu. When Harlan insists that there are aliens, Chris calls them Spiders from Mars, referencing David Bowie. The music playing in the mall is Strangers in the Night. During the spider attacks, the music is a low-key, menacing version of Itsy-Bitsy Spider. The film received mixed reviews as a goofy, witty movie, though some complained that it ran out of steam in the second half. The spiders were really quite good and there were a lot of them.