- Despite the fact each game has its respective main villain, the final boss is always Bowser in some form, whether possessed or on his own:
- Superstar Saga has Bowletta, with Cackletta's soul possessing Bowser.
- Partners in Time has Shrowser as the Post-Final Boss, with him having devoured Elder Princess Shroob's mushroom.
- Bowser's Inside Story has Dark Bowser, which is the form the Dark Star takes with Bowser's DNA.
- Dream Team has, for the first time ever, Bowser on his own, with him having absorbed the Dream Stone to become Dreamy Bowser.
- Finally Paper Jam has Shiny RoboBowser, the combined form of Bowsers from both dimensions.
Fridge / Mario & Luigi