I recommend the novel, Immortal Hunting, to you. Although the female protagonist was not a snake demon, she was also a demon. She was a zombie named Meng Xiaodai, who was pursued by a Western Blood Clan and a female malicious ghost. The male lead was Li Gongfu, dealing with a troublesome brother-in-law and dealing with a series of events in the Heavenly Prison. I hope you like this fairy's recommendation. Muah ~😗