Call of Cthulhu - Sixth Edition - Malleus Monstrorum 

Here are those things which can "eternal lie", and which have lived beyond human understanding for strange aeons. The Cthulhu Mythos is comprised of a complex and broad group of sometimes-contradictory entities, powers, and concepts that encompass the secrets of time, space, and the universe.

this book contains

• Outer Gods:             rule the universe.
• Elder Gods:             are neutral to or possibly rivals to the outer gods.
• Great Old Ones:      are not omnipotent, but nonetheless are godlike and terrible in human eyes.
• Great Ones:             are the gods of Earth's Dreamlands. Do not confuse them with the Great Old Ones.      
• Avatars:                   are variant manifestations of an Outer Go, Great Old One, Elder God or Great One.

This Call of Cthulhu - Malleus Monstrorum book is Published by Chaosium