Kapparot: The Yom Kippur Tradition of Chicken Twirling
For some 1,000 years, many Ashkenazi Jews have observed the same ritual every Yom Kippur Eve — waving a chicken over their head. From the start, the practice was controversial among rabbinical scholars, and even today, it continues to ruffle feathers. (Sorry, couldn't resist).
Source: boulderjewishnews.org