Taken from Episode 70 of The Sopranos. Tony kicks his own bodyguards ass to show his guys that he has still got it. He shows them that he is still a tough guy. It's when you show the people in your employment that you can do anything they can AND you can do it better.
A big fat girl that hangs out with a hot girl and cockblocks every guy that tries to talk to the hot girl. This is done because the big fat girl is a hater and is jealous of the hot girl and wants the hot girl to be lonely and miserable just like her.
Joe: I think I could go home with that fine blonde over there but that ugly fat bodyguard girl keeps cockblocking me . I'm getting no where!
Grant: no worries pimpin, I'll take one for the team and hit on the bodyguard. That will distract her so you can make your move.
Someone (usually a friend) who accompanies you to an in-person meeting arranged via Craigslist to provide support in case of anything going wrong (ex: the Craigslist person being dangerous, creepy, or a scammer). The Craigslist Bodyguard can also simply provide moral support or transportation.
Sam: Are you really gonna meet that mechanic from Craigslist? What if he murders you?
John: Don't worry, James is coming as my Craigslist Bodyguard.