An individual who starts out with a particular group of friends that he/she then becomes tired of being around, thus causing the individual to move on to another friend(s). Then, when he/she is tired of the new friend(s), they move back to the original friend group as a "last resort". The "climbing" continues between large amounts of friends so that the individual is not socially bored.
"Dude where's Joe?"
"He's hanging out with Jim and Mike instead of us now"
"It's ok, he's a friend climber, he'll come back to us soon, and then leave again"