A species of South American killer spider hitches a lift to the U.S. in a coffin and starts to breed and kill.

Molly Jennings: What's wrong?
Dr. Ross Jennings: Metcalf - he's having a seizure.
Molly Jennings: Thank God you didn't examine him this morning.
Delbert McClintock: [after stepping on a spider, a dog barks in the background] Yeah, that's right... I'm bad!
Dr. Ross Jennings: Respect is fine, but actually I've always wanted to be feared.
Dr. Ross Jennings: The itsy-bitsy spider crawled up the water spout; down came the rain and washed the spider out.
Jerry Manley: So how long will it take us to get back to camp?
Doctor James Atherton: What's the matter? You still worried about dinosaurs?
Dr. Ross Jennings: Not the Chateau.
Doctor James Atherton: In this first generation, the original male also produced a queen, and together they will construct a primary nest which the queen will guard. But eventually, she will create reproductive offspring of her own. And when that happens, this town is dead... and the next town... and the next town... and the next one, and so on.
[noticing the dead spider Lloyd took out of the cereal box]
Milt Briggs: What could have killed it?
Dr. Ross Jennings: The shock of seeing Lloyd?
Dr. Ross Jennings: [after killing a spider] Therapy.
Molly Jennings: Why is all the wood rotting?
Delbert McClintock: I'll tell you why. Bad wood.
Molly Jennings: So... what do we do?
Delbert McClintock: Tear out bad wood. Put in good wood.
Delbert McClintock: Would anyone object if I tore this floor out?
Molly Jennings: I would.
Delbert McClintock: False alarm then. Lead on.
Delbert McClintock: Rock and roll!
Dr. Ross Jennings: Milt, why don't you cover the living room.
[sighs]
Dr. Ross Jennings: Chris, why don't you check out back. And uh Lloyd, take the kitchen. And I'll just uh, I'll oversee the uh, I'll just coordinate the uh, I'll just stay right here.
Molly Jennings: I'm sure you knew exactly what you were doing when you took Margaret off those pills.
Dr. Ross Jennings: Like I knew what I was doing when I chose this town... with the country doctor from hell!
Doctor James Atherton: In its original habitat it was confined by geography that isn't true here.
[the General spider is not from Canima]
Dr. Ross Jennings: [Dr. Ross Jennings has just informed his wife that Dr. Sam Metcalf has postponed his retirement, and that he is seeing his only patient Tomorrow]
Dr. Ross Jennings: We're gonna be fine, we'll be alright, just like you said.
Molly Jennings: With ONE patient?
Dr. Ross Jennings: Well, I mean, you know? Maybe I'll get lucky and all of her systems will be ravaged by disease. Ya know, kinda like having seven patients in one.
[scene changes to Dr. Jennings surgery where he has just completed his examination of Margaret Hollins]
Dr. Ross Jennings: Fit as a fiddle, not a damn thing wrong with ya.
Margaret Hollins: Dr. Jennings, I'm sorry.
Dr. Ross Jennings: Oh, sorry? What do ya mean you're sorry?
Dr. Ross Jennings: [under his breath] You think I was hoping you were ravaged by disease?
Doctor James Atherton: What's your specialty, Manley?
Jerry Manley: Football.
Dr. Ross Jennings: What do you wanna bet they're gonna go chase fireflies?
Bunny: Wanna blow up a bullfrog?
Shelley: OK.
Dr. Ross Jennings: Come on, let's go find that spider. And let's find your mom to take care of that spider. Honey, we're in the living room. We need you to kill a spider.
Henry Beechwood: Bobby here, he's a, he's a Bronco star quarterback.
Bobby Beechwood: Hi.
Molly Jennings: Hi.
Henry Beechwood: I taught him to throw a football before he could walk. I coach the team.
Molly Jennings: Nepotism huh?
Edna Beechwood: Actually, we're Baptists.
[Flicks ant off of Manley's knee]
Doctor James Atherton: 24 hour ant.
Jerry Manley: They bite?
Doctor James Atherton: They kill, Mr. Manley, in sufficient numbers.
Dr. Ross Jennings: In my opinion...
Margaret Hollins: In my opinion, Dr. Metcalf isn't aware of the difference between his ass and a hole in the ground
Sheriff Lloyd Parsons: [introducing Delbert to Doctor Atherton] Excuse me. Professor? This is our town exterminator.
Delbert McClintock: Delbert McClintock, infestation management. Always nice to meet a collegue.
Sheriff Lloyd Parsons: Now, he believes he came across one of the offending spiders a couple of hours ago.
Doctor James Atherton: Might you have brought it with you?
Delbert McClintock: Actually, he's probably still at the bottom of my shoe. You really can't tell what it is anymore.
[last lines]
Doctor James Atherton: [while drawing out the general spider] Suppers ready! Come and get it
[said general spider screeches and leaps onto his neck sinking it's fangs into his throat]
Delbert McClintock: [minutes later cries out as James drops from the rafters, cocooned and covered in spiders] They got the professor!
Delbert McClintock: Spiders would find your barn a tad breazy this time of year. In that respect, spiders are a bit like you and me. No, I frankly doubt there are any spiders in your barn.
Dr. Ross Jennings: Well, I frankly know there is Delbert. I saw a web! There is a web in my barn!
Delbert McClintock: ...A web would indicate an arachnoid presence.
Doctor James Atherton: I think this is a new species of butterfly... we could call it Potius Manliae
[Atherton being goofy making in inside joke to Jerry Manley after all the bugs fall from the tree]
Doctor James Atherton: Well that could be the good news.
Doctor James Atherton: [the spiders die soon after biting the victim]
Milt Briggs: Now let's discuss the bad.
Dr. Ross Jennings: Chris, I'm scared to death.
Collins: Yeah, we all are, but our brains secrete a neurotransmitter that enables us to deal with them.
Dr. Ross Jennings: I don't think I have that particular neurotransmitter.