Everyone and Mario

Overview
Due to making in far in both seasons Mario has a lot of interactions and most of them are positive.

Alph
In Lucky Duckies Alph threw his Pikmin at Mario causing Mario to think of Alph as crazy he makes it to the final 2 of the challenge with him and loses against him.

Bowser
They hate eachother outside the competition but don't have much interactions inside the competition however he was happy when Bowser got eliminated in the first season.