Of course, when you think about dancing bears the imagination is immediately drawn to Beorn in
The Hobbit:
Citation :
"If you must know more, his name is Beorn. He is very strong, and he is a skin-changer."
[...]
"He changes his skin; sometimes he is a huge black bear, [...]"
[...]
There was a growling sound outside, and a noise as of some great animal scuffling at the door. Bilbo wondered what it was, and whether it could be Beorn in enchanted shape, and if he would come in as a bear [...]
Later on Gandalf explained where he had gone in the morning:
Citation :
"I have been picking out bear-tracks," he said at last. "There must have been a regular bears' meeting outside here last night. I soon saw that Beorn could not have made them all: there were far too many of them, and they were of various sizes too. I should say there were little bears, large bears, ordinary bears, and gigantic big bears, all dancing outside from dark to nearly dawn. They came from almost every direction, except from the west over the river, from the Mountains. In that direction only one set of footprints led-none coming, only ones going away from here [...]"