Sweater-Clad Colbert sings with Willie Nelson for Christmas Special

The permanently suit-clad Stephen Colbert has traded in his pinstripes for a cardigan sweater, red turtleneck and furry boots. Following the tradition of Andy Williams and Bing Crosby, Colbert hosts his own holiday special in A Colbert Christmas: The Greatest Gift of All, set to air this weekend. Clearly in the Christmas spirit, at the first mention of old holiday specials, Colbert launches into renditions of Williams' Little Altar Boy and Crosby and David Bowie's Little Drummer Boy. The latter was the inspiration for a duet between Colbert and Willie Nelson, who appears -- in one of the more bizarre numbers -- as a tiny wise man in a miniature nativity scene. "This is just some good fun to watch during your egg-nog-induced dementia," Colbert joked in an interview Wednesday. The special finds Colbert far from his Colbert Report set in an obviously made-for-TV room of a mountain cabin dressed for Christmas. Hanging by the fireplace are two stockings, one labelled "Stephen," the other "Colbert."