One principal horror story could be about a haunted house. There are often tales of strange noises, apparitions, and a feeling of being watched. People might experience cold spots or objects moving on their own.
There is a horror story about a mental asylum that was abandoned long ago. People who dare to enter at night report hearing the screams of the former patients, seeing shadowy figures moving in the corridors. It is said that the place is haunted by the tortured souls of those who were mistreated there. This story combines the spookiness of an abandoned place with the history of suffering, making it a very principal horror story.
Well, it might also mean the names of the authors who are principal in creating those stories. Like J.K. Rowling for the Harry Potter series. Her name is associated with those stories in a very important way as she is the one who brought the whole wizarding world to life.
In some cases, the principal might single out the teacher for not following a new school policy in a very harsh way. Let's say there's a new dress code for teachers, and the principal makes a big deal about the teacher not conforming right away, embarrassing the teacher in front of students and other staff.
It could be the school principal doing it as a special activity for the students staying overnight at school, perhaps during a camping event or a sleep - over organized by the school.
I'm not sure which specific principal you are referring to. It could be a principal in a school who likes to read bedtime stories to students during a special event like a sleepover at school.
In 'Lady Chatterley's Lover' by D. H. Lawrence, there is a significant exploration of sexual relationships. The relationship between Lady Chatterley and her gamekeeper is a principal aspect. It was controversial at the time of its publication as it delved deeply into sexual desires and the connection between physical and emotional love, challenging the prudish norms of the era.
It can enhance the bond between the principal (could be a parent, teacher, etc.) and the listeners. When someone reads bedtime stories, it creates a warm and intimate moment.
Once, a principal accidentally walked into the wrong classroom during an important inspection. He started praising the students for a project they hadn't even started yet. Everyone had a good laugh.