Possibly some animal...
2 seconds sound clip from the Fiend Without a Face (1958) movie soundboard.
You can hear this line at 00:19:38.944 in the Blu-ray version of the movie.
Quote context
[...]
- It's as if some mental vampire were at work.
- Where has the brain and spinal cord gone?
- I'm a doctor, Colonel, not a detective.
- There's nothing like this in the books.
- Major Cummings had the best explanation so far: mental vampire.
- Maybe that guy Gibbons was right about the supernatural.
- Well, whatever the explanation, we'll find it. We must find it.
- In the meantime, Doctor, I trust I can rely on your discretion.
- Not to tell the mayor or the townspeople? Of course.
[...]