Riker

Riker is the tritagonist in the film, The Super Mario Odyssey Movie: How John Paul became Dark Blue. He is the brother of Aayla, and John Paul Rivera's best friend. He is the person who tells John Paul Rivera to ask Sid Phillips about the trees, and how to find him, though it is never revealed if he ever knew him personally.

How John Paul Became Dark Blue

He was first see at Gusty Bridges in the Cascade Kingdom with Aayla and they helped John Paul Rivera and Nicolas Duncan when they both were having trouble with Riley.