A variety of horrible poisonous spiders get exposed to a noxious chemical that causes them to grow to monumental proportions.

Chris McCormick: Get back you eight-legged freaks!
Wade: What exactly is that?
Deputy Pete: A spider, man!
Larry: Dude did you piss your pants?
Bret: Come on we got to go! We got to get out of here! They're coming!
Randy: Looks like the only thing going is you dude!
Harlan: There's no way you're telling me that thing back there is from earth!
Chris McCormick: All right! They're spiders from Mars! You happy!
Harlan: No.
Joshua's Parrot: I see dead people, I see dead people...
Joshua: He like's that movie, dunno why...
Mike: Mom, are you there?
Sheriff Sam Parker: Yea, Mike. Is everything ok?
Mike: Don't make any movements or noises. There's a giant tarantula headed your way.
Sheriff Sam Parker: Copy that.
Harlan: Oswald's gun... man, this is the weirdest day of my life!
Harlan: Just because I'm paranoid doesn't mean people aren't following me.
Mike: No one's going to believe me, cause I'm a kid, and they never listen to kid.
Chris McCormick: [on the phone] Operator, you don't understand... it's an invasion! They're here already! They're here!
Harlan: [broadcasting over the radio] Now people "the phones are down" and I know they're gonna tell you that it's a "technical error"!
Ashley Parker: [a jumping spider lands on the roof of the house] What was that?
Sheriff Sam Parker: It's just Pete, he is waiting to come on.
Ashley Parker: I don't think it was Pete.
Randy: She is the sexist sheriff in the whole country!
Harlan: That's the one who busted up my trailer!
Chris McCormick: Shh!
Harlan: I bet you he's their leader!
[last lines]
Harlan: And that my friends is the story of how aliens attacked our sleepy little town. And to this day, people refuse to believe the truth about what happened. They would lead you to believe that I would embellish this story, that I would make it up, but we know the truth. Oh yeah, uh, two, two things I forgot to tell you. One, they never did get that probe near me. And two, as far as Chris McCormick, reopening the gold mines and putting everyone back to work... Well that my friends, is another story altogether.
Deputy Pete: Winchester, 30.06, Mossberg pump, and the Lee Harvey Oswald rifle... Why we have that, I do not know.
Chris McCormick: [after finding a big spider leg] That ain't no cactus!
Sheriff Sam Parker: [to Pete on the phone] Something *ate* your cat?
Chris McCormick: I got a signal!
Harlan: That's great. Now, how about dialing!
Deputy Pete: [trying to lure the cat out of the drywall] Get your furry cat ass out of there.
Deputy Pete: [surrounded by spiders] Hey, you know what? Let's just go back inside. Let's go back inside.
Harlan: [tries door] Locked.
Deputy Pete: That's okay.
Harlan: Plan B?
Deputy Pete: Um... Right. Tell you what, we're just gonna... We're gonna run away.
Harlan: Yeah?
Deputy Pete: Yeah.
Harlan: Okay.
Sheriff Sam Parker: So you're trying to tell me that a giant spider ate Gladys?
Deputy Pete: They're not aliens they're spiders mutated by contaminated waste!
Harlan: That's probably a more logical explanation!
[Wondering what Sheriff Sam Parker is wearing under her pants]
Larry: What do you think? G-String, or underpants?
Randy: I'd say under...
[first lines]
Harlan: Do you know fear?
Chris McCormick: Harlan, get up here!
Harlan: I'm afraid of heights.
Chris McCormick: Heights? Are you afraid of spiders?
Ashley Parker: Mom, I am not you! I'm not gonna get pregnant at 16. I'm not gonna stay here for the rest of my life and be a trailer trash sheriff!
Sheriff Sam Parker: Thanks for the flashback. I really didn't deserve that!
Mike: Take these you'll need them.
Chris McCormick: Perfume?
Mike: Well spiders have a highly developed sense of smell the perfume might confuse them.
Harlan: Great if we die we die smelling nice.