Super Mario 64/Secret Castle Stars

There are 15 secret castle stars (30 in Super Mario 64 DS - see below) which do not appear in regular courses.

Secret Stars

 * Three stars can be gotten from Toad. If you talk to him in the entrance to Hazy Maze Cave, on the second floor under the stairs leading up to the third floor, or on the third floor next to Tick Tock Clock, he will give you a free star.
 * This star can only be found in the Nintendo 64 version. After you have 15 stars and less than 50 stars, a rabbit can be seen hopping around the basement. Catch him and he will give you a star. He will return after you gain more than 50 stars and can be caught again for another star. In some versions of the game it is possible to catch him again, though he will not give you any more than two stars total. In other versions, after you have received two stars from him, he will disappear permanently.
 * There are two stars on The Princess' Secret Slide.
 * Three stars can be found in the three cap levels by collecting all the red coins.
 * There is one star in The Secret Aquarium.
 * Another star can be found in Wing Mario Over the Rainbow.
 * Three stars are found in the three Bowser levels, just collect the red coins.

Super Mario 64 DS Exclusive Stars

 * There is no MIPS in this game, but there are rabbits. After you talk to Toad in the Rec Room, there will be rabbits all over the castle grounds. Eventually, after a certain number of stars, glowing white rabbits will start appearing. Grab 8 of those, and they will give you a key, which opens the white door in the character switch room. This contains a star.
 * Six stars can be found in total in the character levels.
 * An extra three stars in the Bowser levels can be found by pressing the Star Switches.
 * Two more stars are found in the "cap" levels.
 * There is a second star in Wing Mario Over the Rainbow.
 * There are two stars in total in Sunshine Isles and The Secret of Battle Fort.
 * One star can be found if you are Luigi. Go into the room with the Wario painting and grab one of the Power Flowers. Run through the mirror and into the door in the mirror. You will find yourself in an empty room with nothing but a star.
 * Straight after you get Mario, go into the hallway through one of the wooden doors and follow the Boo that you see, straight into the courtyard. It's infested with Boos, but eight of them contain red coins. As ever, collect all eight and you will get a star.