Yes, that's the sign of the werewolf.
2 seconds sound clip from the The Wolf Man (1941) movie soundboard.
You can hear this line at 00:11:19.760 in the Blu-ray version of the movie.
Quote context
[...]
- Tell you what we'll do. We'll take a little walk tonight and we'll talk it over.
- No.
- No!
- Yes, they're fortune-tellers. They pass through here every autumn.
- You know, I haven't had my fortune told in years. How about tonight?
- No.
- Yes, that's the sign of the werewolf.
- That's just a legend, though, isn't it?
- Yes, but like most legends, it must have some basis in fact.
- It's probably an ancient explanation of the dual personality in each of us.
[...]