Super Mario 3D World Hidden Luigis: World Castle
World Castle-1: Fort Fire Bros.
After you defeat the Fire Bro at the end of the level, rotate the camera and look down and to the right, and 8-bit Luigi can be seen inside one of the windows.
World Castle-2: Switchback Ruins
At the Stamp location, shoot a fireball at the wall to the right to find an 8-bit Luigi hiding in the shadows.
World Castle-3: Red-Hot Run
At the end of the level, look at the top of the volcano to spot Luigi in the background.
World Castle-4: Boiling Blue Bully Bell
Take a look at the spiked rollers to spot an 8-bit Luigi.
World Castle-5: Trick Trap Tower
You can find a large 8-bit Luigi on the wall near the first Green Star.
World Castle-6: Rammerhead Reef
After the Checkpoint but before the Warp Pipe, you'll be able to see an 8-bit Luigi hoping on a rock in the distance.
World Castle-7: Simmering Lava Lake
At the start, change the camera angle and angle it to one side of the barrier to spot an 8-bit Luigi on the other side.
World Castle-Boss: Bowser's Lava Lake Keep
During the opening cutscene, look above the entrance to see the 8-bit Luigi.
World Map
If you wait near the beginning of the map, an 8-bit Luigi will appear above the brick behind the gated off lava flow near the Clear Pipe that brought you in.
