You know, it occurs to me that our friend is perhaps a mutation. But of what species, I do not know.

6 seconds sound clip from the 20 Million Miles to Earth (1957) movie soundboard.

You can hear this line at 00:34:58.039 in the Blu-ray version of the movie.

Quote context

[...]

- Well, how will we find him? How will we know him?

- He drives a truck with a house that follows like a goat.

- A trailer.

- Find it as quickly as you can. I'll wait here for the divers.

- Yes, sir. Come on, doc.

- Would you and your men accompany the colonel?

- Of course, general.

- Besides, I have to see a man about a horse. And a half-a-million lira.

- What?

- The canvas has come loose.

- I better stop then.

- You know, it occurs to me that our friend is perhaps a mutation. But of what species, I do not know.

- Here, you catch this on the other side, please.

- There's also the possibility that it might be a type of throwback toward a prehistoric and unknown...

(Marisa screaming)

- Are you hurt?

- No, I-I don't think so.

[...]