"Inca Mummy Girl" is episode four of season two of the television series Buffy the Vampire Slayer, originally airing on The WB on October 6, 1997. The episode was written by former series story editors Matt Kiene and Joe Reinkemeyer (penning their second and final script for the show) and directed by Ellen S. Pressman.

Buffy and Giles are suspicious of Ampata, a Peruvian exchange student staying at Buffy's house, when a fellow student goes missing during a school field trip to the Natural History Museum and a broken Peruvian pictogram-cover plate is found in his place. Meanwhile, after Xander falls head over heels for Ampata, he faces certain death when his love interest is revealed to be an ancient mummy who must kill to stay alive.

As part of a cultural exchange program at Sunnydale High School, students are paired with international students who will live with them for two weeks. In preparation, Buffy (Sarah Michelle Gellar) and her classmates take a field trip to the museum, where they view an exhibit featuring a 500-year-old mummy of an Inca Princess. Buffy reveals her mother (Kristine Sutherland) signed her up for the program, and she has been paired with a male student named Ampata. Xander (Nicholas Brendon) becomes jealous upon learning that Buffy's exchange student is male.

After the class leaves the museum, a student named Rodney (Clayne Crawford) attempts to steal a ceramic plate from the Inca Princess' sarcophagus. In doing so, he accidentally breaks the seal preserving the mummy, which comes to life and drags him into the coffin.

Later, the Scoobies realize Rodney has not returned from the field trip. They sneak into the museum at night and are confronted by a man dressed in traditional Inca clothing wielding a sword. He attacks them but quickly retreats. Upon examining the sarcophagus, Willow (Alyson Hannigan) observes that the mummy now has braces, leading the group to conclude that the mummy drained Rodney's life force and left his body behind.

Buffy realizes she is running late and rushes to the bus station with Willow and Xander to meet Ampata. Meanwhile, the Inca mummy lures the real Ampata away and drains his life force. When Buffy and her friends arrive, the Inca Princess (Ara Celi) — now appearing as an attractive teenage girl — poses as Ampata. Since no one has seen a photo of the exchange student, they assume the gender difference is a misunderstanding with the exchange program. "Ampata" is taken to Buffy's house, where Xander quickly becomes smitten with her. She appears to return his affections, which makes Willow visibly jealous.

At school, Cordelia (Charisma Carpenter) makes plans to meet Devon (Jason Hall) at the dance that evening where his band, Dingoes Ate My Baby, will perform. Sven, the Swedish exchange student staying with Cordelia, obediently stands nearby. Cordelia complains to Devon that Sven does not speak English. After they leave, Devon discusses Cordelia's attractiveness with his friend and bandmate Oz (Seth Green), who remains unconvinced. Devon teases Oz for being too picky, saying that as the band's lead guitarist, he could date anyone.

Meanwhile, Willow and Xander discuss their costumes for the upcoming costume dance. Willow is excited, while Xander is intent on making an impression on Ampata. Buffy and Ampata arrive at school, and the group meets with Giles (Anthony Head), who has been researching the markings on a fragment of the broken Inca seal. He asks Ampata, as a South American native, if she can assist with a translation. Ampata hesitantly examines the artifact and identifies the word "bodyguard." She explains a local legend about a warrior who was entombed with the Inca Princess to protect her from anyone who might harm her.