Herbert Clegg

Professor Herbert Clegg was an entertainer who had a mind-reading act, only to find to his dismay that he was developing real psychic powers such as clairvoyance and telekinesis. The Third Doctor, who had become interested in researching psychic energy, discovered his secret, then contacted him and requested his assistance in his experiments. Clegg used psychometry on the Brigadier's wristwatch, the Doctor's sonic screwdriver, and a letter from Jo Grant, but when he read the Metebelis crystal and saw visions of giant spiders, he died of fright-induced heart failure. (TV: Planet of the Spiders)

Behind the scenes
Clegg's first name was given as Herbert on-screen, but as Hubert in the novelisation and the novel The Left-Handed Hummingbird.''