It's only a snake.
4 seconds sound clip from the Indiana Jones and the Last Crusade movie soundboard.
You can hear this line at 00:04:07 in the Blu-ray version of the movie.
Quote context
[...]
- Oh, boy! I'm thinkin' about raisin' my dead mama, dig down and put it on her bony finger!
- That cross is an important artifact. It belongs in a museum.
- Run back and find the others.
- Tell Mr. Havelock that there are men looting in the caves.
- Right. Run back... Mr. Havelock... The sheriff...
- What, what are you gonna do?
- I don't know. I'll think of something.
- Dig with your hands, not with your mouth.
[...]