you mean on sm64ds? get to the mirror room and stand in front of the giant mirror until king boo shows up. Don't get too close just stand a little bit away from the mirror.
If you mean the mirror room where you unlock Luigi (in Big Boo's Haunt) when you fall to the room, just go forward and touch the mirror with Mario, then wait. You'll have to battle King Boo to unlock him.
you can't.
Look in the mirror. Your reflection should change to Luigi. Defeat King Boo and Luigi is yours.
the rabbit king is in the white room in the mirror room
Go into Boo's Mansion,go to the room with a tipping floor,stand on the ? block,backflip in the direction of the door,go into the door and you will see a picture of Luigi(the picture in the mirror room is FAKE!!!!!)You will have to follow the sound of King Boo's maniecal laugh.Once you make it,drop into the hole on the top and go up to the mirror and walk around it for a few.Then you will see an illusion image of Luigi and King Boo will appear.He doesn't do a lot of attacks,but he will try to trick you by becoming invisible to the mirror and actual world.Just watch where he and you are(another illusion is that when you see Luigi in the mirror,it actually marks where you are.)When you get the key just go to where you get Mario and BAM!!!!!You get the Man in Green!
Win 1st place in Mirror Mode Star Cup.
i don't know but try winning all cups on mirror mode
There are two "mirrors", the one by Snowman's Land and the one in the Boo battle to get the Luigi Key. The Snowman's Land mirror can be passed through by getting the Power Flower as Luigi and going through the mirror. There is also a Secret Star through the reflected exit door. The mirror in the boo battle reflects King Boo's location (his shadow is also on the floor).
finish the star cup on mirror mode ok ok that's how i pretty sure
its where the picture of king boo goes
its where the king boo pic will go
Mario must enter the door with no number or star and follow King Boo. Using the power floor Mario must float up to the platform to confront King Boo. Once he defeats King Boo using the reflection in the mirror he will get the Luigi key. This key unlocks Luigi as a playable character.