Also known as a naughty or nice list, Santa Claus' good or bad list traditionally lists the names of all the children in the world and notes their behavior over the past year. Well-behaved children receive gifts from Santa, while poorly-behaved children receive bags of coal.
The tradition of a naughty or nice list began with the Nordic legend of a sorcerer who rewarded good children while punishing bad ones. The idea also appeared in Germanic legends in which Santa Claus was accompanied by Krampus, a demon-like creature who kidnapped naughty children while Santa handed out gifts to good children. Popular Christmas carols like "Santa Claus Is Coming To Town" include the concept that Santa often consults his list to keep track of who's been naughty or nice.