One of the most unique days in Lithuania - Užgavienės (Shrovetide)! It is a traditional Lithuanian celebration intended to shoo away the winter. On this day a lot of people, especially kids, dress up wearing scary masks to shoo away the winter. It happens every year on a different day. The stamp could be either on of the masks, the fight between Kanapinis and Lašininis or the burning of Morė.

Here is some more information on it: https://www.etno.lt/en/shrovetide

Pictures: Some of the masks used on the Shrovetide. The fight between Lašininis and Kanapinis. The burning of Morė.