I... don`t wanna picture that. But knowing KC, if he could make a kikimora attractive (In real life lore those things are hideous) then I can`t see how he could not make Cthulhu sexy.
Based on what was talked about in the last book (scholar on way to mist continent, swallowed by sea) I have a strong feeling the next installment is going to have both deep sea monster girls and mist continent monster girls
Besides that imagine shub niggurath as some kind goat mamono similar to an echidna or hastur being either a slime or Scylla subspecies due to his looks. He’s also called the peacock king so maybe a harpy mamono.