Darren Lamb
Darren Lamb is literally the worst agent in the history of acting. Incapable of breaking an act, his usual negotiating tactic is to agree with whatever anyone else says or, more likely, suggest someone other than his client for the part. He is very good at deducting his 12.5% commission, however. His skill at his profession can be summed up by the fact that he once left his office phone unplugged for two days without noticing.
Darren is, of course, played by Stephen Merchant in Extras.