What is "cthylla"

Cthylla (the Secret Daughter of Cthulhu) is a fictional character in the Cthulhu Mythos of H. P. Lovecraft. Cthylla was created by Brian Lumley, who originally mentioned her in his Titus Crow novel The Transition Of Titus Crow ( 1975), though he never actually described her. Tina L. Jens, however, depicted Cthylla as a gigantic winged-octopus in her short story "In His Daughter's Darkling Womb" ( 1997).

Cthylla's name may be a reference to Scylla, a sea monster from Greek mythology.