Historical clue formulations

• Partner of Vixen in "A Visit From St. Nicholas" — 2015-12-01
• High-stepping horse — 2012-12-11
• Cavorter — 2003-12-25
• Member of an annual team — 2001-10-25
• Vixen's mate — 1994-11-27
• Vixen's mate — 1994-05-13