Bobtail

"Bells on Bob's Tail Ring" is almost identical to the line from Jingle Bells, which leads me to wonder if 'bobtail' means what I think it does, which leads to Bobtail, leader of the pack:

The Wolves of Paris were a man-eating wolf pack that killed forty people in Paris in 1450. The animals entered the city during the winter through breaches in its walls. A wolf named Courtaud, or "Bobtail", was the leader of the pack. Reports of the animal suggested it was reddish in color. Eventually, the wolves were killed when Parisians, furious at the deaths, lured Courtaud and his pack into the heart of the city. There the Parisians stoned and speared the wolves to death in front of the Notre Dame Cathedral. 

Map of Paris, France, 1422