The "killer in the backseat" is a popular urban legend that warns drivers about a potential threat from someone hiding in their vehicle. The story typically involves a driver who feels uneasy or notices strange behavior, only to discover that a dangerous person is lurking in the backseat, waiting to attack. This legend serves as a cautionary tale, emphasizing the importance of vehicle safety and awareness. It encourages individuals to check their backseat before entering their car and to remain vigilant while driving, especially in isolated areas. The tale has been retold in various forms, often highlighting the element of surprise and fear.