This is a mug shaped like the Necronomicon, a book first introduced in the Cthulhu Mythos by H.P. Lovecraft, and portrayed here as seen in the Evil Dead film franchise.

The Necronomicon, also referred to as the Book of the Dead, or under a purported original Arabic title of Kitab al-Azif, is a fictional grimoire (textbook of magic) that is sentient and evil -- said to be bound in human skin.

Middle of Beyond produced this mug in a Flesh Variant (brown), a Cabin Variant (darker brown with black wash), or a Blood Variant (red).