The Curse of Yig
H. P. Lovecraft
 Based in Oklahoma around 1880, a newly arrived couple learn about the local legends surrounding a "Snake God", Yig, who takes vengeance on anyone who kills a serpent by killing them or turning them into a half-snake monster. The husband has a snake phobia which isn't helped by the wife disturbing a nest of rattlesnakes. The husband and wife go through rituals to keep Yig away, but in the end it fails and in fear the woman kills her own husband in the dark, thinking he is Yig. She is taken to an asylum, and dies there... But not before giving birth to a half-snake creature.