Mummering is a Christmas-time house-visiting tradition practised in Newfoundland and Labrador, Philadelphia U.S.A, and in isolated patches of Ireland especially Fingal. 

Also known as mumming or janneying, it typically involves a group of friends or family who dress in disguise and visit homes within their community or neighbouring 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. They may poke and prod the mummers or ask them questions. To make this a challenge for the hosts, the mummers may stuff their costumes, cross-dress and dress ridiculously. Once the mummers have been identified, they remove their disguises, spend some social time with the hosts, and then travel as a group to the next home.