|Well, congrats. You discovered it. You get to name it.|
Although this article is based on canonical information, the actual name of this subject is conjectural.
This ritual was performed by Madge Carrigan and Edward Carrigan (both of them are Hold Nickar, Teutonic Pagan Deities of Winter Solstice), for appeasing themselves and renew their powers. The ritual seems only performed once a year, when solstice, which coincides with Christmas.
Much of the details of the ritual were uncertain. A few identified aspects were creation of wreaths out of meadowsweet, and the killing of people who bought the wreaths as sacrifices. The victims were abducted via their house's chimney and eventually killed for their blood.
Recent History Edit
When Madge and Edward found Sam and Dean snooping around in their blood-splattered basement, they took the brothers prisoners and started their ritual preparation for sacrifice. The ritual needed an altar which consisted of some candles, plates, sharp objects to obtain the victim's blood, and may other unidentified objects. During the ritual, Edward pulled out one of Sam's fingernails and was about to pull one of Dean's teeth.
However the ritual was not completed because they were distracted by the doorbell, and the brothers were able to escape their bonds. Dean stabbed Edward with a branch from a Christmas tree while Sam stabbed Madge with another branch, killing them.