Holy shit! I am brazilian and I didn't know any of this!
Granted, I am from São Paulo, but it's not like I don't know stuff like Boto (which funny enough Jontron
mentioned in one of Sonic 06 episodes)
And for those who don't know it; Boto is a type of pink river dolphin (pic related) and legend says that he'd transphorm at night into a beautiful dude, seduce girls, especially virgins, and get them pregnant (sometimes killed? I don't remember)
The reality of it is actually way grimier; it was a way of uncles and dad to toss around the fact that they raped their daughters/nieces. Awful, awful shit.
And btw, just to add to the shit pile: There was this urban legend here in Brazil from the late 90's/early 2000's about evil people with AIDs infecting people by leaving syringes with HIV positive blood at random places.
IT ACTUALLY FUCKING HAPPENED RECENTLY.
A dude was actually going around the subway and other crowded places and infecting random people by attacking them with a syringe (mostly women, btw)
I remember being super paranoid because I go often to the places the attacker used to go, and I saw this very sketchy dude and I walked faster. The next day, the police sketch of the attacker was virtually identical to the guy I saw. I guess it could just be a coincidence (he had a pretty generic face and I was in a hurry), but man, my blood chilled instantly.