"Nackles" is a 1964 short story by Donald Westlake. It was almost adapted for The Twilight Zone (1985).
A man reflects on the disappearance of his sister's abusive husband Frank, a disappearance he blames on a vicious Yuletide character Frank invented — a black-clad Child Eater called Nackles.
- Abusive Parents: Frank prefers that his kids stay completely silent and never cross his path, and when threatening them with Santa Claus' displeasure doesn't strike him as a stern enough motivator, he comes up with Nackles.
- Bad Santa: A cruel father invents Santa's evil counterpart to keep his children in line. Nackles, he tells them, is a black-clad tunnel-dweller in a mine cart drawn by goats, who every Christmas takes the naughty away in his sack to be eaten. The power of belief turns Nackles real, but the only person he takes is his creator.
- Clap Your Hands If You Believe: The narrator (Frank's brother-in-law) ultimately seems to believe despite his own wishes that the belief of the children who had been frightened by Nackles brought him to life.
- Defeat Equals Friendship: Early in the story, the narrator tells how he beat Frank with a baseball bat to get him to stop abusing his sister. Oddly (from his point of view) this actually made Frank like him more.
- Domestic Abuse: Frank hits his wife Susie, only stopping once her brother comes over and gives him a beating. Even afterwards, he doesn't make for pleasant company.
- Freudian Excuse Is No Excuse: Susie tries to justify her husband's behavior by saying that it's the stress of having to be an insurance salesman when he'd really rather be back on the football field. The narrator observes to the reader that he sells cars and would like to be president, but he doesn't hit women because of it.
- Hoist by His Own Petard: Frank invents Nackles to scare his kids into staying quiet and out of his way around Christmas and spreads the story to a number of other people. He doesn't count on the power of the children's belief turning Nackles into a reality, or on the fact Nackles will have to take someone and his kids are too well-behaved.
- Ironic Nursery Tune: After voicing his suspicions that the belief of children who have been told the story will soon make Nackles real all over the country, the narrator quotes a line from "Santa Claus is Coming to Town."
- Lean and Mean: Frank describes Nackles as extremely tall and thin and very nasty.
- Maybe Magic, Maybe Mundane: The narrator never actually sees what happened to Frank and the police suggest the mundane explanation that he simply abandoned his family. The narrator thinks Nackles may have taken him because he can't imagine Frank leaving his sister without doing a lot of yelling about it or without taking his beloved car. It's never settled either way.
- What Does She See in Him?: The narrator cannot figure out why his sister Susie married Frank. He says he could blame it on the blindness of love, but that would beg the question of how she fell in love with him.
- Wife-Basher Basher: After discovering his sister's black eye, the narrator goes to talk to Frank with a baseball bat.