The Ghost Hitchhiker
The story goes that a man stops for a hitchhiking girl and drives her home. When her turns to the backseat to say farewell, the girl is gone. After doing some research, the man learns that very same girl had been dead for years due to a car crash in the very spot he stopped for her.
According to stories, there are alligators within the network of sewers underneath New York City. It is said a young boy kept an alligator as a pet and flushed it down the toilet, where it grew and became violent.