'The Pack' Story Code '4V06' by Matt Kiene and Joe Reinkemeyer

While on a rare school field-trip to the local zoo, the pack of school bullies - Tor, Rhonda, Lance, and their leader, Kyle - confront Xander in the quarantined hyena exhibition. But before a fight can break out, they are all taken over by a strange force; they leave the enclosure with yellow eyes and much more aggressive personalities. Xander acts particularly cruelly towards Willow, who is crushed by his malicious behaviour. Worried by their friend’s change of personality, Buffy and Giles do some research and discover an African tribal myth concerning hyena spirits that possess men. The bullies - now with Xander as a member of their group - take the school’s mascot, Herbert the Pig, and eat him. When Buffy encounters Xander on his own he begins to make overtly sexual advances towards her; concluding that this is far from Xander's normal behaviour, Buffy is forced to lock him in the rare book cage in the corner of the library for his own protection. Meanwhile, the rest of the pack are summoned by Principal Flutie to his office, where he begins to reprimand them for their shocking behaviour; however, they then turn on him and devour him as well. Buffy and Giles return to the hyena exhibit at the zoo and talk to the exhibit's keeper, who is able to tell them how to reverse the curse that has been placed on Xander and the others. Buffy leads the pack to the zoo, where the keeper has set up a sacred circle required for the ritual; he draws the hyena essence out of the possessed teenagers, but plans to double-cross Buffy by drawing it into himself, making him all-powerful. He is successful, but at the last moment is thrown into the hyena pit by Buffy and a recovered Xander, and is slaughtered by the very animals he hoped to become.

Sarah Michelle Gellar (Buffy Summers), Nicholas Brendon (Xander Harris), Alyson Hannigan (Willow Rosenberg), Charisma Carpenter (Cordelia Chase), Anthony Stewart Head (Rupert Giles), Ken Lerner (Principal Flutie), Eion Bailey (Kyle), Brian Gross (Tor), Jennifer Sky (Heidi), Michael McRaine (Rhonda), Jeff Maynard (Lance), James Stephens (Zookeeper), David Brisbin (Mr. Anderson), Barbara K. Whinnery (Mrs. Anderson), Gregory White (Coach Herrold), Justin Jon Ross (Joe), Jeffrey Steven Smith (Adam), Patrese Borem (Young Woman)
Directed by Bruce Seth Green

TX (US): 7th April 1997
TX (UK - Sky One): 7th February 1998
TX (UK - BBC 2): 3rd February 1999

Notes:
*Featuring Buffy, Xander, Willow, Giles and Cordelia