I'm not a historian, but I'll answer anyway.

In The Call of Cthulhu, in the second chapter, The Tale of Inspector Legrasse, the narrator describes a small statuette idol of Cthulhu recovered from some of its cultists in a Louisiana swamp:

"A monster of vaguely anthropoid outline, but with an octopus-like head whose face was a mass of feelers, a scaly, rubbery-looking body, prodigious claws on hind and fore feet, and long, narrow wings behind."