Bowser's SCARIEST Secret? - New Super Mario Bros. (DS)

"Bowser's SCARIEST Secret? - New Super Mario Bros. (DS)" is a video by Kjolt and the fourth installment of the "scary mario secrets" playlist and series. It was published on April 1st, 2026. Just like other videos in the series up to this point, it focuses on the game New Super Mario Bros. and is a satirical parody of old game hoax videos made by kids online. However, unlike the other videos, the "secret" is not made up; rather it is a detail within the vanilla game that cannot even be classified as a secret.

In the video, Kjolt plays through all of 1-Castle to prove the haters wrong and collect all the star coins on the first try. As the April Fools' Day subversion in this video is that the secret is entirely real and well-known, the entire rest of the level is a custom-made remix of the original level featuring new obstacle layouts, and Splunkins and Pokeys as enemies. No attention is drawn to this and the level is played normally as if it were unchanged.