The Polterkitty is an antagonist making her debut in Luigi's Mansion 3. She is Hellen Gravely's pet cat ghost who helps her through the game by stealing the elevator buttons from Luigi as the green clad hero makes his way through the hotel. Because of what she does, the Polterkitty also serves as a recurring boss in the game.
In her base form, Polterkitty is a cat with purple fur and light blue eyes. She also possesses three tails. She also wears a white pearl collar with an elegant pendant around her neck, possibly to indicate that she already belongs to Hellen.
While Polterkitty doesn't appear at first in the game like Steward, she is first seen after Luigi rescues one of the toads, resting on Hellen Gravely's lap while the latter watches Luigi's progress in the hotel.
Unlike most bosses in the game, Polterkitty is not tied to any one floor, appearing after two other bosses - Kaiju (for Director Morty's movie on the eighth floor) and Johnny Deepend (on the 13th floor) - and dealt with; both times, she grabs the recovered Elevator Button, forcing Luigi to track her down.
Fighting Polterkitty is at first a matter of finding her. Luigi must use his Dark Light to follow her tracks, and then find her hiding place by interacting with objects. Once Polterkitty is found, she stays out of reach, attacking Luigi only when he turns his back to her. If he stays still, Polterkitty reveals her true form in order to pounce, that of a larger, man-shaped, demonic cat; this is the one time she is vulnerable to the Strobulb, meaning the player has to wait for this to happen before trying to stun her. When Polterkitty's health is reduced to only 1 hp, she flees to another room, regaining full health. The first time, the player must repeat this process three times in three different rooms in two different floors (Floor 7 and Floor 8), at which point Polterkitty relinquishes the key and flees back to her master. The second time, Luigi must again do it three times, but in three different floors (13, 12, and 11); upon doing that, he finally captures her.
Polterkitty herself does not appear on Floor 10, but that floor has a hidden golden statue of her that Luigi can find using his Dark Light. If he does so, Polterpup will appear and run around the statue until it tips over, shattering and releasing some treasure.
In the end credits of the game, after Hellen has also been captured, Polterkitty is being held - and still being lovingly petted - in the same containment cell with her master.
- Polterkitty serves as an evil counterpart to Polterpup and both share a similar behavior.
- Polterkitty's habit of only attacking a foe whose back is turned is oddly similar to that of the Boos, who traditionally cannot attack a foe who looks them in the face.
- Polterkitty is one of the few antagonists in Luigi's Mansion to be an animal-based ghost, the other is Captain Fishook, who manifests as a shark in battle.
- When Luigi finally captures her, he will have reduced her HP to zero a grand total of nine times, a reference to the myth of cats having nine lives.
Luigi's Mansion: Dark Moon
Luigi's Mansion 3