Michelle Obama jumped right into the holiday spirit with an epic dance-off with Santa Claus.

The former first lady, known for her dance moves, made a surprise appearance Thursday at a children’s hospital in Denver, Colorado.

When asked by a child at Children’s Hospital Colorado to name her favorite dance move, Obama replied, "I don’t think any of my favorite dance moves have names to them. I just move to the music. I just like to move."

Former first lady Michelle Obama dances after a patient at Children's Hospital Colorado in Aurora, Colo., asks her about her favorite moves Thursday, Dec. 13, 2018.(Thomas Peipert/AP) Former first lady Michelle Obama dances after a patient at Children's Hospital Colorado in Aurora, Colo., asks her about her favorite moves Thursday, Dec. 13, 2018.

A child in the audience then showed her how to do the “Orange Justice” dance from the popular Fortnite video game.

Obama, 54, not only got up and danced, she also got Santa to dance and encouraged everyone in the audience to dance too.

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The former first lady started her visit to the hospital a bit more traditionally, reading "Twas the Night Before Christmas" in front of a packed crowd of patients and their families and hospital staff.

Former first lady Michelle Obama reads "The Night Before Christmas" to children at Children's Hospital Colorado in Aurora, Colo. on Dec. 13, 2018.(Thomas Peipert/AP) Former first lady Michelle Obama reads "The Night Before Christmas" to children at Children's Hospital Colorado in Aurora, Colo. on Dec. 13, 2018.

While she was first lady, Obama famously mom-danced with Jimmy Fallon, danced to Bruno Mars' "Uptown Funk" with Ellen DeGeneres and even busted a move with vegetable dancers for her "Let's Move" campaign.

(MORE: Michelle Obama surprises a dance class at her former high school and it's amazing: ABC News Exclusive)

More recently, Obama has danced at stops on her book tour for "Becoming," her memoir that is now the bestselling book of 2018.

It was Obama's "Becoming" book tour that took her to Colorado Thursday. She was interviewed by actress Reese Witherspoon in "Becoming: An Intimate Conversation" at the Pepsi Center.

Since the book's Nov. 13 release, Obama has appeared in cities from Chicago to Los Angeles, interviewed at each stop by the likes of Oprah Winfrey, Tracee Ellis Ross and Phoebe Robinson of "2 Dope Queens."

(MORE: Meghan Markle meets with Michelle Obama at London stop of 'Becoming' book tour)

Obama announced earlier this month that her tour will be extended into 2019. She has events scheduled for the New Year in more cities across the U.S. as well as international stops including Paris, London, Amsterdam, Oslo and Stockholm.

"Becoming" has topped the adult nonfiction rankings in the United Kingdom, Germany, France, Italy, Holland, Spain, Denmark, Norway, Finland and Greece, the book's publisher Penguin Random House announced last month.