Edward Mordake (or Edward Mordrake) is the character of a popular urban legend, named as the 19th century heir to an English peerage. He supposedly had an extra face on the back of his head, which could neither eat nor speak, although it could laugh and cry. But, as seen on the only picture we have, he could not possibly have a skull, even less a proper brain, demonstrating therefore that the image is a hoax. Edward begged doctors to have his "demon face" removed, because, supposedly, it whispered demonic words to him at night, but no doctor would attempt it. He committed suicide when he was 23.  The description of Edward Mordake's condition is somewhat similar to those of Chang Tzu Ping and Pasqual Pinon. Both Mordake and Pinon are featured as the 2 Very Special Cases on a list of 10 People With Extra Limbs or Digits in The Book of Lists edition of 1976.
The 1896 text Anomalies and Curiosities of Medicine  mentions a version of the story and Edward has now been featured in many texts, plays, and songs.  Tom Waits wrote a song about Edward Mordake titled "Poor Edward" for his album Alice.
This is the story as told in Anomalies and Curiosities of Medicine:
The following well-known story of Edward Mordake, though taken from lay sources:—
"One of the weirdest as well as most melancholy stories of human deformity is that of Edward Mordake, said to have been heir to one of the noblest peerages in England. He never claimed the title, however, and committed suicide in his twenty-third year. He lived in complete seclusion, refusing the visits even of the members of his own family. He was a young man of fine attainments, a profound scholar, and a musician of rare ability. His figure was remarkable for its grace, and his face—that is to say, his natural face—was that of an Antinous. But upon the back of his head was another face, that of a beautiful girl, 'lovely as a dream, hideous as a devil'. The female face was a mere mask, 'occupying only a small portion of the posterior part of the skull, yet exhibiting every sign of intelligence, of a malignant sort, however'. It would be been seen to smile and sneer while Mordake was weeping. The eyes would follow the movements of the spectator, and the lips 'would gibber without ceasing'. No voice was audible, but Mordake avers that he was kept from his rest at night by the hateful whispers of his 'devil twin', as he called it, 'which never sleeps, but talks to me forever of such things as they only speak of in hell. No imagination can conceive the dreadful temptations it sets before me. For some unforgiven wickedness of my forefathers I am knit to this fiend—for a fiend it surely is. I beg and beseech you to crush it out of human semblance, even if I die for it.' Such were the words of the hapless Mordake to Manvers and Treadwell, his physicians. In spite of careful watching, he managed to procure poison, whereof he died, leaving a letter requesting that the 'demon face' might be destroyed before his burial, 'lest it continues its dreadful whisperings in my grave.' At his own request he was interred in a waste place, without stone or legend to mark his grave."
- Anomalies and Curiosities of Medicine, pp. 188-189. George M. Gould, Walter L. Pyle. Kessinger Publishing. ISBN 978-0-7661-3211-5 (2003)
- The People's almanac presents the book of lists, p. 314. David Wallechinsky, Irving Wallace, Amy Wallace. Morrow. ISBN 978-0-688-03183-1 (1977)
- "EDWARD MORDAKE – "Poor Edward"".
- Hoskyns, Barney (2009), Lowside of the Road: A Life of Tom Waits, Random House, p. 405, ISBN 978-0-7679-2709-3
- "Edward Mordake – ‘Poor Edward’". J. Tithonus Pednaud. Retrieved 2008-11-11.