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.

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.

Battle
Serpci mainly attacks by manipulating 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; if Luigi is nearby, they will rear up and strike at him. A successful hit will cause Serpci to briefly emerge and taunt Luigi, but a missed attack will stun the snakes, giving Luigi time to destroy them with wind 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; the dust she kicks up indicates where she is coming from. Later in the battle, she creates giant fists of sand to ram and crush Luigi; 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, giving him an opening 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 sucked in, also supplying Luigi with the elevator button.

Trivia

 * Serpici's design is based off of the Egyptian ruler Cleopatra.