Possible Clues:

• Reindeer in peril, about to be substituted for good
• Ballroom performer
• One taking steps to provide first part of down clue's requirement, we hear
• Hoofer
• Second reindeer mentioned in “A Visit From St. Nicholas”
• One familiar with Charleston peters out of centrespread
• Terpsichorean mover
• Bussell or Baryshnikov
• Member of Santa's team
• Some European runs to cradle head of collapsed ballerina