- Barbara Wright: [about the Doctor] Oh, I do wish he wouldn't talk in riddles!
- Ian Chesterton: So do I.
- Barbara Wright: [finding the dead giant earthworm] Doctor! Doctor! It's a huge snake!
- Dr. Who: What? Yes.
- Barbara Wright: Let's call the others.
- Dr. Who: Oh yeah. Wait, wait, wait. Yes, I think it's dead.
- Barbara Wright: It's a fantastic size.
- Dr. Who: No eyes. No head. The skin is interesting, isn't it?
- Barbara Wright: Interesting?
- Dr. Who: It's so dull, not scaly.
- Barbara Wright: Doctor, Doctor, are you sure it isn't just sleeping?
- Dr. Who: No, no. It's quite dead. Death has its own particular posture and appearance. Yes, yes.
- Ian Chesterton: [after finding the giant ant] I wonder what sort of a world could produce an insect that size.
- Ian Chesterton: All right. What's your theory, then?
- Susan Foreman: These things haven't been made bigger. We've been made smaller.
- Dr. Who: As I said my dear, it's fortunate for all of us that everything is dead.
- Susan Foreman: [seeing the giant cat which is very much still alive] Grandfather!