Dolly Parton stopped by The Tonight Show Starring Jimmy Fallon on Thursday (Nov. 29) to join him for a hilarious holiday medley that was infused with the holiday spirit -- and perhaps, Parton joked, a bit of grandma's moonshine! Readers can press play above to watch the pair cut up against the backdrop of some Christmas favorites.

Fallon opens the lightning-round mashup medley with "Winter Wonderland," and then Parton takes over with "Rockin' Around the Christmas Tree." Fallon ends the song with the line, "Deck the halls with boughs of DOLLY," and without stopping to catch their breath, the festive duo moves on to "Jingle Bell Rock."

Next, Parton feigns devastation when Fallon breaks the bad news that "Grandma Got Run Over By a Reindeer," and the pair quickly moves on to "Sleigh Ride." Finally, Fallon flubs "We Need a Little Christmas" and nearly doubles over in laughter before Parton saves him for the finale. Parton and Fallon burst out laughing repeatedly during the performance, keeping the audience in stitches with their improvised adaptations of the beloved Christmas carols.

Parton appeared on The Tonight Show to promote the soundtrack for Dumplin', a  new Netlfix film about a plus-size girl who throws her hat into the ring for a beauty pageant to prove a point to her former beauty queen mother, played by Jennifer Aniston. The soundtrack came out on Nov. 30, and includes both Parton classics reinterpreted as duets with an A-list roundup of singers (including Sia, Miranda Lambert and more) as well as six brand-new tunes penned by Parton and longtime collaborator Linda Perry. The accompanying film is due for release on Dec. 7.

See Dolly Parton + More Country Stars Then and Now