21+ Only!

Fox's look in Star Fox Zero is arguably the most "perfected" look to him, however I do think his Star Fox 64 depiction is so synonymous with how the public portrays him as that I just went for his 64 design (I know I used his 64 3D design for this collage, but I think in this case it doesn't matter as 64 3D is a near 1:1 remake of the N64 game).

For Falco, I went with the 1993 game design. In my opinion, it's the design from the original game that had the least amount of changes when comparing to Star Fox 64 and Star Fox Zero, so this is where I decided to honor that game.

Slippy had his own tie-in spin-off game from Star Fox Zero in the form of Star Fox Guard, so naturally this is what I thought fit best for him.

That leaves Peppy with the new 2026 game design, which I think is perfect. Out of all the crew members' designs from the new game, I think Peppy resembles his Star Fox 64 and Star Fox Zero incarnations the most, plus I think his new voice is doing a phenomenal job as far as I can tell.

If you noticed, I went with designs that felt familiar and cohesive together, despite the fact that they're all from different games retelling the same story in very different ways.

…Particularly because it provides a reason why Mario and Bowser team up during that match.

As it turns out, that tournament match between Mario & Bowser VS. Peach & Daisy is actually the epilogue to Adventure mode.

Adventure mode starts out with the Mushroom Kingdom Tennis Tournament not even starting yet and Daisy becoming sick.

The story eventually pits Bowser as a villain again with him scheming again and is part of the final boss of Adventure mode.

After they defeat Bowser, Mario and the gang remember that the tournament is happening and Daisy's now well enough to join.

And while there's no actual cutscene to go along with this, the end credits show a picture of Mario lending a helping hand to Bowser after defeating him—Mario deciding to help Bowser up despite everything that he did. And it's the last picture to show up in the end credits too.

When the credits end, a short cutscene is played where it reveals that the tournament match between Mario & Bowser VS. Peach & Daisy is about to start.

And that's how we got to here:

So in conclusion, Bowser teams up with Mario in tennis because Mario was kind enough to help him out in the end.