Someone who thinks that just because you brought beer to a social outing that is an opportunity to come over and drink beer for free. Usually not from your geographic area. They will usually introduce themselves and then immediately ask for a complimentary beverage. After this they quickly excuse themselves and rejoin their own friends. They repeat this process over and over again approaching a different friend of yours each time, until your beer supply is exhausted.
Hey man what's up? My name Jc and I'm from South Congress, got a beer I can have? I'm not a beer beggar, I will get you back as soon as I get a car and some money!