Gerald Peach
From Tardis Wiki, the free Doctor Who reference
Professor Gerald Peach was one of the guests at the weekend party hosted by Lady Clemency Eddison in 1926.
Biography
Earlier on, Gerald had found out about Lady Eddison having a son born out of wedlock. It turned out to be the Reverend Arnold Golightly, who then turned out to be a vespiform. Gerald Peach was killed by Golightly, by a blow to the head with a lead pipe, just as he was confirming his suspicions in the library. (DW: The Unicorn and the Wasp)
He is the most obvious parody of a Cluedo character, Professor Plum. This was noted by Donna, stating "Professor Peach, in the library with a lead pipe?"