You'll be able to spit nails, kid. Like the guy says, you're gonna eat lightning, and you're gonna crap thunder.
7 seconds sound clip from the Rocky (1976) movie soundboard.
You can hear this line at 01:29:28.163 in the Blu-ray version of the movie.
Quote context
[...]
- And you made me feel like a loser! I'm not a loser!
- What?
- You're not a virgin! You let him into your pants! She's busted!
- You're gonna become a very dangerous person.
- Oh, Rock. I want you to meet our cutman here, Al Salvani. Take a look at his eye.
- Cover up. Things'll be okay.
[...]