Kacper is the Polish form of the name Casper, which is Persian in origin and means 'Treasure Keeper'. The Polish spelling is unusual in Britain and the forms Casper or Kasper are more frequently used.
Casper, a variant of Caspar, is considered one of the traditional names of the Biblical Magi (Kings). The name is derived from the ancient Chaldean word "Gizbar" meaning "Treasurer". The transition was Gizbar>Gasbar>Gaspar>Caspar>Kaspar.