This folk saying was collected from a friend, who was born and raised in Monterrey, Mexico and is 20 years old. El chamuco is a Mexican folk saying mostly used to as a slang term referring to the devil. It often comes with religious undertones, and some versions are very detailed; for example, some people believe that his body is on fire, has one cat leg and one chicken leg, and smells strongly like copper.
It was used in her household in different ways. Her mother would often say things like, “go to sleep right now or el chamuco will eat you.” The hostile tone of that type of threat-like statement made her feel very scared as a child.
However, people also used it to refer to an evil or angry person. When her mother got angry, her father would say “if you get any angrier the chamuco is going to come out of you.” It soon became a running joke with her siblings to refer to their mother as el chamuco when they wanted to tease her. She would get really angry, which they just thought proved their point.
Even though I wasn’t familiar with el chamuco specifically, my parents had similar ways of getting me to listen to them, like el cuco, which was used in the same context as el chamuco and I would think could even be a variation of it. As I pay closer attention to Latin American sayings and legends, I am beginning to see that parents tend to scare their children into behaving, which is really interesting. I think Latin American parents are very strict and more religious than the average American, which is reflected in these folk sayings.