Stuff of Legends
Urban legends are a genre of folklore comprising stories circulated as true, especially as having happened to a "friend of a friend" or family member, often with horrifying or humorous elements. These legends can be entertaining but often concern mysterious peril or troubling events, such as disappearances and strange objects. They may also be confirmation of moral standards, or reflect prejudices, or be a way to make sense of societal anxieties, such as maybe unwittingly peeing in a pool and having a red or purple cloud of shame following you around as the water changes color.
Urban legends are most often circulated orally and most of them have passed through the years with only minor changes to suit regional variations - maybe where you live it is not alligators in sewers, but giant snakes? And maybe that isn't even an urban legend... In any case, have you heard the one about the "free parking downtown"?