|Appearances||The Hounds of Baskerville|
|Portrayed by|| Russell Tovey|
- "Mr. Holmes, they were the footprints of a gigantic hound!"
- ―Henry Knight, The Hounds of Baskerville.
When he was a child his father was killed in front of his eyes. Traumatized, he was convinced a monstrous hound killed his dad. Later it is revealed that Bob Frankland was the murderer. Mr. Knight knew too much about Dr. Frankland's experiments with chemical weapons. Frankland wore a t-shirt with a picture of a dog and the acronym H.O.U.N.D. which was the reason why Henry rationalized the killer into a monstrous hound. Frankland haunts him during the night, by turning on the security lights repeatedly, leaving Henry terrified.