A mummer is a costumed performer or reveler who participates in a variety of folk celebrations. The term "mummer" has its roots in medieval Europe, where it referred to performers who wore masks and costumes and participated in mummers plays, which were popular pastimes for the poor. In Philadelphia, the Mummers Parade is an annual event held on New Years Day, where thousands of mummers march in elaborate costumes alongside floats built by competing clubs. The parade is the longest-running continuous folk parade in the United States. The Mummers derive their name from the Mummers plays performed in Philadelphia in the 18th century as part of a wide variety of working-class street celebrations around Christmas. In Newfoundland, "mummering" is a Christmas folk tradition where groups of people disguise themselves and visit homes within their community or neighboring communities during the twelve days of Christmas. If the mummers are welcomed into a house, they often do a variety of informal performances that may include dance, music, jokes, or recitations. The hosts must guess the mummers identities before offering them food or drink.