Captain Fishook

Captain Fishook is the thirteenth boss encountered in Luigi's Mansion 3, who haunts The Spectral Catch and guards both the thirteenth floor's elevator button and the yellow Toad's portrait. He is one of three non-humanoid bosses in the game, the others being Polterkitty and King Boo.

Appearance
Captain Fishook is a ghostly great white shark wearing an eyepatch which conceals the thirteenth floor's elevator button, his “good eye” being red and pupilless. He has a golden earring on his dorsal fin, and his right fin is replaced with a hook-like scythe. He appears to have a gold tooth.

Captain Fishook appears shortly after embarking on his ship, where he swims up. He then reveals the thirteenth floor elevator button underneath his eyepatch before possessing the ship's deck.

Battle
Fishook will start by possessing the deck of his ship, attempting to suck in Luigi from below. To force Fishook out of the deck, Luigi must push three powderkeg bombs thrown by Oozers through his gullet in succession.

Afterwards, Luigi needs to evade Fishhook's scythe and lunging attacks, and specifically time his Strobulb flash so that it affects Fishook's right eye (as his left eye has an eye patch), giving Luigi the chance to attack.

Upon draining his HP to 100, Fishook will change tactics and possess his ship's stern, attempting to overturn the ship ninety degrees backwards; Luigi must use the Suction Shot on a board with a bullseye icon near the ship's bow to avoid the attack. As Fishook continues to possess the stern instead, the Oozers now throw the powderkeg bombs from in front of Fishook instead, and it now takes six powderkeg bombs shot at Fishook's gullet to force him into the open. After taking three hits from the powderkegs, Fishook will tilt the ship again, with the board now moving left and right, making it harder to cling onto. After being exposed for the final time, Fishook gains an attack where he jets through the deck of the ship trying to hit Luigi, which can be dodged by bursting. Upon defeating him, he will struggle to flee only to be forced in downward. Luigi will then obtain the thirteenth elevator button as well as release the yellow Toad atop the ship's stern.