My informant M’s scariest legend was the one of La Carreta Nagua. Legend has it that in the middle of the night while everyone was asleep a cart would slowly roll through the village streets. It was being pulled by two skeletal horses and commandeered by the Grim Reaper himself. If anyone was awake or in the streets by the time the cart rolled through, they would be claimed by the Grim Reaper and taken to the Underworld.
This legend is based on the slavery and colonization of Native American tribes. In many pueblos, Native Americans who heard the carts of colonizers looking for slaves would know to run or hide. If they were to be captured, they most likely would have been taken to the mines; after years of enslaving Native Americans it was eventually deemed not worth it because Native Americans would commit suicide instead of live through the terrible means they were placed in.
When asking what M thought of the story, she said that as a child she was terrified to be up too late because she didn’t want to be taken by La Carreta Nagua. She would have consistent nightmares about being abducted too. I enjoy this legend because it is based in real events that occurred for centuries and was an actual threat to their very existence. Thus it’s a very good example of folklore saving people’s lives.
I found an article that details the multiple variations of the legend here: https://leyendas-nicaraguenses.blogspot.com/2007/03/la-carreta-nagua.html