Toad in the Whomp's Fortress Room (SM64)

The Toad in the Whomp's Fortress Room informs Mario of the Cap Switches and the Course Menus.

"It was Bowser who stole the Stars. I saw him with my own eyes! He’s hidden six Stars in each course, but you won’t find all of them in some course until you press the Cap Switches. The stars you’ve found will show on each course’s starting screen. If you want to see some of the enemies you’ve already defeated, select the stars you recovered from them."