Annah
Annah is an NPC who stood on the south side of the Green Line in Croatoa. She is not a contact, but it appears that she will grant a fifth costume slot as some point. Her coordinates were (|860.5, 0, 2252).
As of the September 20th, 2006 patch, Annah has been removed from the game. She is currently on the test server.
Annah did appear as a scientist holding a scroll.
When clicked, Annah said:
These are magical days indeed. To show your worth to the Ravenwing Cabal, I ask that you bring me some souvenirs of the season of the witch. These are costume pieces from some of the more popular costumes of the day. Bring me one Statesman Mask, one Lord Recluse Helmet, one Back Alley Brawler Gloves, and one Hamidon costume. If you do this, I will grant you access to another Costume Slot.