Prince Mush from Paper Mario: The Thousand-Year Door is one of the secret bosses that can be accessed on the Nintendo Switch. Originally, players had never been able to fight him until now with the newest remake. Stemming from Chapter 3, this champion challenges you to a rumble after completing the game. However, be warned, this fight will not be easy. Preparing to face him head-on will require the right level, badges, and items.

https://screenrant.com/paper-mario-thousand-year-door-how-to-beat-prince-mush/