Ep 40. Koopa Klaus

Mario and Luigi are feeling festive as Christmas approaches in Brooklyn. However, their holiday cheer is soon thwarted when they receive a video message from Princess Toadstool, who informs them that Bowser has taken control of the North Pole, capturing Santa Claus along the way. As a result, Christmas is in danger of being cancelled indefinitely.

Determined to help, Mario, Luigi, and Princess Toadstool make their way to the North Pole, accompanied by Toad, in order to confront Bowser and rescue Santa. Once there, they discover that Bowser has taken on the guise of "Koopa Klaus" and has brainwashed Santa's elves into building weapons instead of toys. In addition, Bowser has enlisted the help of his Koopa Troopas, who are dressed as "Koopa Klaus's elves", and have taken control of Santa's workshop.

The group hatches a plan to infiltrate the workshop by disguising themselves as Koopa Troopas. However, their cover is blown and they are forced to fight their way through Bowser's minions. Along the way, they encounter a familiar face - Donkey Kong, who has also been brainwashed by Bowser and is working as one of his henchmen.

Mario and Luigi eventually make their way to Bowser's throne room, where they engage in a final battle with Koopa Klaus himself. With the help of some magic mushrooms and some strategic teamwork, the brothers are able to defeat Bowser and free Santa from his clutches.

In the end, Santa thanks Mario, Luigi, Toad, and Princess Toadstool for their brave efforts in saving Christmas. As a reward, he gives them presents and even invites them to join him for a ride in his sleigh. The group happily accepts and joyfully flies off into the night sky, filled with the holiday spirit.