The Odyssey is the main form of transportation for Mario in Super Mario Odyssey. It allows Mario to travel to different kingdoms throughout the game, but only if Mario has collected enough Power Moons from a kingdom.
Mario is able to buy items from the Crazy Cap shops to decorate the inside and outside of the Odyssey.
Mario can also dress up in his costumes from Crazy Cap in the Odyssey using his wardrobe.
If Mario has taken any damage, going inside the Odyssey will automatically bring him back up to full health.
There are several ways in which to enter the Odyssey, through the hatch on the roof, the pipe at the back, a reference to the main source of travel in most Mario levels, and of course, the trusty door.