The H.P. Lovecraft Wiki
The H.P. Lovecraft Wiki

Template:Inmythos This subject contains information from the "Lovecraft Circle" Myth Cycles, and while guided by HPL are not based on his work alone.

When I unfastened the blackened silver clasp and opened the yellowed leaves a coloured drawing fluttered out—the likeness of a monstrous creature resembling nothing so much as a squid, beaked and tentacled, with great yellow eyes, and with certain abominable approximations to the human form in its contours.
~ H.P. Lovecraft & William Lumley , The Diary Of Alonzo Typer

An Ancient One is a humanoid that has squid-like features and exists only partly in the physical, material dimension.