Marzanna (Polish), Morana (Czech, Slovene, Serbian, Croatian), Morena (Slovak, Russian), Mara (Ukrainian, Belarusian), Morė (Lithuanian). Also known as Maržena, Moréna, Mora or Marmora is a Baltic and Slavic goddess associated with seasonal rites based on the idea of death and rebirth of nature.
Burning of Mara signifies the death of winter in eastern Slavia. Czechs and Slovaks also burn her. I am not sure for what reason.