To get the Pimp Hat go to the Darkwood Bordello and then find the deeds by the old oak tree (at the Bordello)(use the Spade.) Now you can "Pleasure Yourself" for free. Do this and then go behind the Bordello to find a Demon Door it should now open for you and inside is the Pimp Hat. (Although it isn't all that useful... it sort of relates to the use of the Fishing Hat)