Henry Jekyll and Edward Hyde

Doctor Henry Jekyll and Mr Edward Hyde were two identities of a single man who created a potion to separate the "good" and "evil" sides of his personality. (COMIC: Dr. Jekyll and Mr. Hyde)

Biography
Throughout his career as a medical student and a doctor, Jekyll struggled with his cravings for the "evil side" of life. To help himself control these impulses, he invented a potion which transformed him into Hyde, contorting his bones and changing his facial appearance; the alteration could be reversed by drinking an antidote. Although Jekyll recognised Hyde's monstrocity and tried resisting the change, he began to transform himself into Hyde to escape the boredom of his life.

Free to commit crimes with impunity, Hyde would drink, smoke, and commit vandalism. One day, upon knocking over a child, he was surrounded by a mob and paid off the girl's father with a £25. This was seen by Jekyll's lawyer, Utterson, who recognised Jekyll's signature on the check and confronted Jekyll about it. Despite brushing off Utterson at first, after Jekyll lost control again and Hyde brutalised an elderly woman in the park, Jekyll confessed the secret of his potion. (COMIC: Dr. Jekyll and Mr. Hyde)

Legacy
The Fourth Doctor knew Utterson's account of Jekyll and Hyde, (COMIC: Dr. Jekyll and Mr. Hyde) and the Fifth Doctor referenced it to Nyssa, Tegan, and Hayter. (TV: Time-Flight)

Robert Louis Stevenson wrote a book about Jekyll and Hyde entitled The Strange Case of Dr Jekyll and Mr Hyde. (AUDIO: Medicinal Purposes) In the 1890s, Henry Gordon Jago and George Litefoot believed it deserved a theatre revival. (AUDIO: Stage Fright)

Abby McPhail named Doctor Jekyll as an example of a doctor who wasn't there to cure people. She suggested he really needed to work on his bedside manner. (AUDIO: Hysteria)

In the Land of Fiction
Hyde was one of the members of the Sisyphean Society's senior circle in the Land of Fiction. The Master killed him along with the other members of the Society. (COMIC: Character Assassin) Years later, Missy again defeated Mr Hyde, this time as part of an unrelated plan to conquer the Land by installing L. Frank Baum as its new Master. (PROSE: The Wonderful Doctor of Oz)

Behind the scenes

 * Jekyll and Hyde originate in Robert Louis Stevenson's novella The Strange Case of Dr Jekyll and Mr Hyde.
 * He was played by Dougray Scott in a 2008 television film, Dr. Jekyll and Mr. Hyde.
 * The 2007 series, a sequel to Stevenson's story, was written by Steven Moffat. In a more recent TV drama, in 2015, Stephanie Hyam plays the characters' love interest.
 * David Hasselhoff portrayed Mr Hyde in the 2001 DVD recording of the musical.