The lone friend who is generally not liked by your entire group of friends, yet people "put up with him/her." The Andy tends to find out where everyone is hanging out, despite noone inviting him/her. The Andy typically ends the fun at parties, and ruins any conversations he walks into, usually because they are about him. The Andy talks behind everyones back (talking shit), and buys them bad gifts at birthdays and Christmas.
"Dude, how the hell did Andy find us?"
"Shit, the Andy's coming? I'm going home."