"The Pack" is the sixth episode of season 1 of the television series Buffy the Vampire Slayer. The episode aired on The WB on April 7, 1997. The episode was written by story editors Matt Kiene and Joe Reinkemeyer, and directed by Bruce Seth Green.

When Buffy and the rest of Sunnydale High endure the annual field trip to the zoo, Xander and some other kids sneak into the quarantined hyena exhibit, but leave in an altered state. It's up to Buffy, Giles and Willow to discover the cause behind Xander's bizarre behavior and reverse the transformation before it's too late. Meanwhile, Xander's new aggressive demeanor doesn't play well with his old friends.

The students from Sunnydale High School are on a field trip to the Sunnydale Zoo. Buffy (Sarah Michelle Gellar) is confronted by a group of bullies who pick on her for being expelled from her previous school. The group then targets another student, Lance. When Principal Flutie (Ken Lerner) interrupts, Lance refuses to identify the bullies, prompting them to include him in their plan to explore the off-limits hyena exhibit.

Buffy sees them heading into the restricted area and tries to intervene, but Xander (Nicholas Brendon) volunteers to handle it himself, considering it unrelated to Slayer duties. As he leaves, Buffy and Willow (Alyson Hannigan) realize he might need help and attempt to follow, but are stopped by the zookeeper, Dr. Weirick (James Stephens), who informs them the hyenas are in quarantine after arriving from Africa. He also shares a local legend from the Maasai, claiming that hyenas are known to call people by name in order to isolate and devour them.

Inside the exhibit, the bullies attempt to throw Lance into the hyena enclosure, where a large hyena with glowing green eyes appears. Xander intervenes and pulls Lance to safety. The group — now including Xander — stands atop a large painted symbol on the ground. Lance flees as the others begin laughing ominously.

The next day at the Bronze, Willow eagerly awaits Xander. Buffy acknowledges Willow's crush and admits she finds Angel (David Boreanaz) attractive but feels she cannot pursue a relationship with someone who is rarely around and primarily focused on fighting vampires. When Xander arrives, he behaves strangely — taking Buffy's food without asking and sniffing her, noting that she has bathed. He also joins the bullies in laughing at a fellow student being mocked. They observe the bullies mocking a boy, and Xander laughs at their cruel joke.

At school, Principal Flutie chases a pig through the halls before Buffy catches it. He introduces the pig as Herbert, new school mascot. As Flutie discusses school spirit with Buffy, Xander walks past, and Herbert suddenly begins squealing in fear, prompting Buffy to take notice of the pig's reaction.

In gym class, Coach Herrold announces a game of dodgeball. Buffy and Willow are placed on the same team, while Xander joins the bullies. Xander and the bullies quickly eliminate all opponents, including Willow, whom Xander hits harshly with the ball. Near the end, Buffy is the last player remaining on her team, but instead of targeting her, the bullies throw balls at their teammate Lance.