Found this on the internet!!!! I believe "Millie" is a real live mule who does these acts quite regularly, hoping to source some more information soon!
A light-hearted tale for Yule featuring Millie the mule and a very naughty jester - as performed in the days of old the medieval knights. Performances at 12 noon, 1.30 & 2.30pm.
Sunday 23 December 2007 - Sunday 23 December 2007
Cost: Free event. Parking £3
Venue: Sherwood Forest Country Park (link will open a new browser window)