A group of so called "bad boys' or gangsters, usually on bikes and without helmets, that are followed by a nerd. The said nerd has helmet, glasses, braces, etc. and is obviously tying to be hardcore. Upon seeing a group of this sort, it is common to exclaim "It's a nerd of bad boys!"
Sophie, Lilli, and Jebediah are walking down the street.
Sophie: whoa, did you just see that whole nerd of bad boys?
Lilli: yeah, totally