Grouchy Possessor

The Grouchy Possessor is the first boss Luigi faces in the Nintendo 3DS game Luigi's Mansion: Dark Moon. He is fought in the Gloomy Manor's Cellar where he has taken over the body of a large spider. The Grouchy Possessor is the cause of the spider web infestation inside the mansion and he also has the second Dark Moon piece.

Ghost Container Description
''This magnificent ghost possessed a spider queen in his efforts to hold on to his Dark Moon piece. Luigi really had to use his noggin to outsmart this spectre! He has his moments.''

Appearance
The spider he possesses is large and purple. She has four green eyes, a red abdomen, and red and purple legs.

Outside of the spider, the Grouchy Possessor looks like a white ghost with a large horn in the middle of his head, he has three layers of skin, the first one is white, which is seen when Luigi lures it out of the large spider for the first time, the second is yellow and the third is red. The Dark Moon piece can be seen inside of him.

Attacks
During battle, the Grouchy Possessor may attack in several different ways. If Luigi approaches the large spider, it will attack Luigi with its front legs. While Luigi is pulling the webbing from the Possessor's web, it will summon red spiders to attack Luigi. The large spider will also spit out purple goop from its abdomen that travels in a straight line. If Luigi is hit while he is dragging the webbing, he will let go of it and the process needs to be repeated. Each phase change, the large spider will attempt to ram into Luigi. The Grouchy Possessor itself must be sucked up three times, one for each layer of skin - each time Luigi overpowers it, it will abandon its outer layer and retreat to its host to resume the battle.

While outside of the spider, the Grouchy Possessor will attack by charging into Luigi. After this attack, the Grouchy Possessor will be temporarily stunned. It is highly possible for Luigi to stun the Possessor and capture it before it attempts to ram Luigi.

Strategy
In order to force the Grouchy Possessor out of its spider host, Luigi must flash the Strobulb at the arachnid when its eyes are open. The large spider will retreat to its web, allowing Luigi to suck up a wad of silk from the web with the Poltergust 5000. Luigi must then drag the ball to a nearby suit of armor holding a torch. The armor will attempt to strike Luigi with its torch, but its long windup allows the heroic plumber to move out of the way and trick the armor into striking the web ball instead. This will ignite the silk and eventually burn the spider's web, dropping it onto its back and forcing the Grouchy Possessor out of its body.

When the Grouchy Possessor is out of its host, Luigi must dodge its charge attack and stun it with the Strobulb before attempting to suck it up. Since the Possessor has infinite HP, Luigi has to build up the Power Gauge and then use it against the Grouchy Possessor. If Luigi does this successfully, the ghost will lose its outer layer and retreat to the large spider, taking control of it once again.

At the beginning of the second phase, the Grouchy Possessor will move the large spider to ram into Luigi, who must keep to the sides of the walls to avoid being hit. After this attack, the large spider will move deeper in the Cellar, breaking down a wall to reveal a second web with a silk ball at the bottom. This time, Luigi must first use the Poltergust 5000's blow function on the chandelier to spin a brown wad of webbing into a torch, which allows it to burn down a web on the right wall that covered a suit of armor with a spear. Luigi must then use the Strobulb on the large spider to stun it before dragging the wad of webbing to the spear-wielding suit of armor, all while avoiding the spider's attacks. As before, Luigi must provoke the armor to attack before moving the silk ball into its path, allowing the armor to stick the silk on its spear. When the armor returns to its idle position with the silk on its spear, Luigi can spin the chandelier again to set the brown webbing alight and spin it into the ball on the spear, burning the large spider's web and sending the Grouchy Possessor out of its host again. Luigi can then repeat his previous strategy against the Possessor to remove its second layer, revealing its red-tinted true form.

After losing its second layer, the Grouchy Possessor will possess the spider one last time. After repeating its charge attack, the spider will break through another wall and perch in front of one final web, this one with two web balls nearby. Luigi must grab the closer web ball (in front of the large spider) and take it to the first suit of armor with the torch while avoiding red spiders and two falling pillars. Once the ball is ignited (in the same way as the webbing in the first phase), Luigi must return to the back of the room (using the burning web ball to destroy oncoming spiders) and burn the web on the right wall, freeing another suit of armor with a torch.

With this done, Luigi can repeat his strategy from the first phase, blinding the large spider with the Strobulb before dragging the silk ball behind her to the newly-freed suit of armor. After tricking the armor into hitting the silk, the web will burn, the spider will fall, and the Grouchy Possessor will be forced into the open once more. Luigi must repeat his previous tactics against the ghost (dodge its charges, flash it with the Strobulb, and build up power while trapping it with the Poltergust 5000) to finally suck it up for good and retrieve the Dark Moon piece it held.

After Luigi collects the piece, the large spider shrinks down to normal size, freed of her possession at last. She runs off with a horde of red spiders, freaking Luigi out momentarily before he can finally celebrate his victory.

Trivia

 * The Grouchy Possessor is the only one of the possessor ghosts to be seen at the end of the game.
 * He is also the only possessor ghost that actually controls something that is alive without his help (the spider queen).