What is a nerf herder?

United States
March 31, 2007 4:19pm CST
Han & Leia - Han and Leia from the Star Wars trilogy films
Okay so I'm watching Star Wars and I wonder what a nerf herder is! Leia calls Han a scruffy nerf herder. A what? Do any of you guys have any ideas on what a nerf herder is? Perhapses a nerf is an unknown creature or something...