It's a really tough fight, and you'll need to use everything you've learned so far to beat them.
View Luigi's Mansion 3 How To Find Boos
Pictures. How to catch a boo? In luigi's mansion 3 a boo will appear on all floors on which you have already defeated the boss ghost (hence, there is no boo to catch on the very top floor.
Luigi S Mansion 3 Hidden Boos Usgamer from cdn.gamer-network.net
One of the hidden collectibles in luigi's mansion 3 is hidden boos. Luigi uses the slam move to knock the boos around. They can be spotted if you are careful enough to spot items moving by themselves.
Used the strobulb on all strobe flowers in the garden.
You'll unlock them by doing found the royal coffers in the castle macfrights. To see the list of boos in the other games go here: Go to the very back of the corridor on the first floor, to a glowing, locked door. Regardless, we will detail the general area or room that they can be found in.