Cuca is one of the main mythological beings of Brazilian folklore. She is popularly known as an ugly old alligator girl who steals naughty children.
The origin of this legend is in a dragon, Coke From Portuguese legends, this tradition was brought to Brazil at the time of colonization.
Legend has it that Cuca robs children who disobey their parents. Cuca sleeps one night every 7 years, and when she gets mad she gives a shout that you can hear 10 leagues away. Because Cuca is barely asleep, some adults try to frighten children who resist sleeping by saying that if they don't sleep, Cuca will catch them.