One scary element could be the unexpected and grotesque events that occur in the toe story. For example, there might be some sort of strange transformation related to the toe that is both disturbing and frightening.
Well, often in these kinds of stories, the setting plays a big role in the scariness. In the 'Toe Story' from 'Scary Stories to Tell in the Dark', it could be a dark and isolated place where the events with the toe take place. This creates an atmosphere of unease and dread. Also, the way the characters interact with the toe, whether it's a sense of being haunted by it or having something malevolent associated with it, is really spooky.
The unknown is always a major source of scariness in such stories. In the 'Toe Story', we might not know exactly where the toe came from or what dark powers it holds. It could be the idea that there are hidden forces at work, and the characters are at the mercy of this strange toe. The descriptions of the toe itself might be quite disturbing too, like if it has an unnatural appearance or emits an eerie feeling. All these aspects combine to make the 'Toe Story' in 'Scary Stories to Tell in the Dark' a scary one.