I always heard the jester was Dylan, but I don't quite agree with Dylan's interpretation. The court jester is part of a tradition of people who challenged and critiqued power; however, they did so from within power. Maybe it's the latter point that Dylan objects to, but I don't necessarily think that it's the worst comparison that could be made.
Interesting. In that case I think Dylan fitted the bill nicely back then. I thought of the joker as kind of a fool... I guess I think Jabber is a fool.