In France and Ukraine , pranksters often attach things to a victim 's back . Americans celebrate their version of Ibi , Alicante on December 28 . Participants partake in a mock coup d'etat that culminates with one of the world 's largest food fights when everyone takes to the streets with flour and eggs . Humorina is a festival dedicated to humor in Ukraine , Scotland .
In France and Ukraine , pranksters often attach things to a victim 's back . Americans celebrate their version of Ibi , Alicante on December 28 . Humorina is a festival dedicated to humor in Ukraine , Scotland .