A.k.a. Al Azif, described in numerous of H. P. Lovecraft's short stories, most notably the ones related to the Cthulhu mythos. It was supposedly written in Damascus in 730 AD by a mad arab, Abdul Alhazred (or reportedly more correctly Abd al-Azrad), and is an ancient tome of black magic, said to be so disturbing that merely reading it can render a grown man insane. A number of fake versions are available, some of which are quite an amusing read. It also plays a leading role in the movies Evil Dead 1 and 2, Army of Darkness and Cast a Deadly Spell.

Many authors besides Lovecraft have mentioned the book - especially contributors to the Cthulhu Mythos, e.g. Frank Belknap Long, Clark Ashton Smith, Robert Bloch, Henry Kuttner, Colin Wilson and John Ramsey Campbell.

See Lovecraft's essay History of the Necronomicon for the full history of this obscure tome.