Jesper is the main protagonist of the critically acclaimed animated Christmas film "Klaus". He's portrayed as a spoiled and selfish postman who learns compassion and selflessness when teaming up with a lonely woodsman named Klaus to begin the Santa Claus tradition.
This is probably of little interest to people outside Norway, but in the tale about Kardemommeby (cardamomtown) by the Norwegian author Thorbjørn Egner, there are three thieves named Kasper, Jesper and Jonathan.