It's the Chair in Indefinite Studies, the Senior Wrangler and the Lecturer in Recent Runes that I totally can't peg down as characters.
Ever listened to Steven Briggs read them? He's fantastic. Although I muddle up the above characters as well when actually reading, Mr Briggs really gives them their own identity (sometimes a teensy bit like other characters, but hey). Amazing, that man
OT: I can't think of a character name that bugs me. Sorry. Moist von Lipvig is supposed to be an awful name I think and Perdita; well, sounds like a stage name to me.
Oops, wait. I don't particularly like the name Jewelz (or something like it - I listened to the book, haven't read it properly yet) from UA.