"Must Be Santa" was written by Hal Moore and Bill Fredericks. The song was first released in 1960 by Mitch Miller. In 2009, Bob Dylan covered Brave Combo's arrangement as part of his holiday album, Christmas in the Heart
. Dylan told Bill Flanagan: "This version comes from a band called Brave Combo. Somebody sent their record to us for our radio show [Theme Time Radio Hour]. They're a regional band out of Texas that takes regular songs and changes the way you think about them. You oughta hear their version of 'Hey Jude
This song is reportedly based on a German drinking game, with the lyrics taking on a 'call and answer' structure: "Who's got a beard/That's long and white?/Santa's got a beard/That's long and white." Dylan's version intersperses the names of former US presidents into the list of Santa's reindeers: "Dasher, Dancer, Prancer, Vixen/Eisenhower, Kennedy, Johnson, Nixon/Dasher, Dancer, Prancer, Vixen/Carter, Reagan, Bush, and Clinton."