Popplewick
Popplewick Senior may be more appropriate as there were two versions. See Popplewick Junior
Talk about it here.
Mr Popplewick Senior was the identity used by the Valeyard while in the Matrix.
Popplewick Senior was a Victorian Clerk and claimed to be an assistant to "Mr J.J. Chambers" in the Fantasy Factory. Sporting an explosive quill behind the ear, Popplewick was a stickler for procedures which was used to delay the Sixth Doctor from seeing Mr J.J. Chambers. He wore a blue coat with facial hair and glasses unlike his double Mr Popplewick Junior. The Senior Mr Popplewick was above the Junior Popplewick in rank but below Mr J.J. Chambers.
Popplewick was held hostage by Sabalom Glitz, and his true identity was revealed by the Sixth Doctor, who pulled off his mask. He declared that he knew as the performance was too perfect.
Senior was the Valeyard in a virtual disguise created by the Matrix. Due to the rules of the Matrix being anything but ordinary the Matrix portrayed the guise as a "mask" despite being a projection of the Matrix. (TV: The Ultimate Foe)
