Ready for the mosh pit, shaka brah.

normally used when somebody not associated with the punk/thrasher style wears this style for any particular reason (e.g. your clothes smell of chlorine) without attempting to fit into the style. usually said by the person wearing the outfit either in an attempt to fit in or as a joke.

Chloe: Lookin' sick Max! A couple tats, some piercings and we'll make a thrasher out of you yet.
Max: Ready for the mosh pit, shaka brah.
Chloe: Maybe not. Go on down and say hi to Joyce. Free breakfast!