Serpci

Serpci is the eleventh boss encountered in Luigi's Mansion 3, who haunts the Tomb Suites and guards the eleventh floor's elevator button.

Appearance
Serpci is an orange female ghost styled after ancient Egyptian royalty, particularly a queen or a pharaoh such as Cleopatra.

Luigi first finds her by opening her sarcophagus in her room, which awakens her. She then activates a trap that sends Luigi down to the Pit Chamber, forcing him to make his way back up to the top of the pyramid.

Luigi stumbles upon Serpci's room again by accident after mimicking a pose in his likeness engraved on the wall. She then laughs before leaving the room.

After Luigi returns to the Sandy Grand Hall, Serpci pranks him by blowing him a kiss from behind and spraying sand on him, before forming a sand tornado to create a sand mound in the likeness of her face, becoming- “one with the sand”.

Battle
Most of Serpci's attacks rely on the manipulation of the sand mound she uses as a shield. Her main offense involves creating four large cobras out of sand that sprout from the top of the mound, striking Luigi if he is near. On a successful hit, Serpci will briefly emerge and taunt Luigi, but a missed attack will temporarily stun the snakes, granting Luigi a small amount of time to destroy them with a gust from his Poltergust G-00. As Serpci takes damage, the cobras can attack multiple times in succession; when they rear up, their eyes will flash once for each strike they will make before becoming stunned.

Serpci can also attack by burrowing under the ground and leaping out to try and crush Luigi under the sand mound, while also creating dust particles to emerge in another spot, indicating where she is arriving, also later will absorb even MORE sand, making it more difficult to defeat her. Later in the battle, she creates giant fists of sand to ram and crush Luigi, however these can be destroyed in a similar manner to her snake constructs.

To beat Serpci, Luigi needs to vacuum sand from the mound protecting her until it collapses and exposes her. She responds by summoning several small sand cobras around herself, which will fire small projectiles straight ahead of themselves before dissipating. Luigi must blow the projectiles off course with his Poltergust or dodge them, allowing him to stun Serpci with the Strobulb and begin depleting her HP. Upon being defeated, she'll adopt a resting pose, with her lips puckered and arms crossed over her chest as she's being sucked into the Poltergust G-00, also supplying Luigi with the elevator button.

Trivia

 * In the Central Chamber, there is a gargantuan statue of Serpci, however, the head of the statue, due to unknown circumstances, is missing. This may foreshadow the fact that Serpci recreates her image in sand in similar proportions, only this time, everything but the head is missing.