1. Warner Bros. really wanted the show to be called Slayer. Creator Joss Whedon refused.
2. Other actresses who auditioned for Buffy Summers included Katie Holmes, Selma Blair and Charisma Carpenter, who went on to play Cordelia…which was what Sarah Michelle Gellar auditioned for before being cast in the titular role.
3. In the unaired pilot, Willow (eventually inhabited by Alyson Hannigan) was played by Riff Regan. The 25-minute pilot presentation is basically the bane of Whedon's professional life, as he said it "sucks ass" in an interview with IGN.
4. Ryan Reynolds could've played Xander…but turned the role down. And clearly was never heard from again.
5. Nathan Fillion auditioned for Angel in 1996, but the role of Buffy's first vampire love went to David Boreanaz. Fillion later would play the evil priest Caleb in season seven and became one of Whedon's go-to collaborators, starring in his cult favorite series Firefly.
6. Whedon revealed that he chose the iconic theme song after Hannigan made him listen to the Nerf Herder track.
7. Spike could've been a Southern vamp! James Marsters originally auditioned with a Texas twang, but producers decided to make the platinum blonde vamp a Brit, with his English co-star Anthony Stewart Head (who played Buffy's watcher and father figure Giles) coaching Marsters. Originally set to be killed off in five episodes by Angel, Spike ended up becoming the male lead in later seasons.
8. Marsters had to bleach his hair every eight days for almost six years to maintain Spike's iconic hairstyle.
9. The character of Oz wasn't the first time Seth Green played Hannigan's boyfriend: They were a couple in My Stepmother Is An Alien in 1988.
10. But Hannigan ended up finding love IRL on-set with Alexis Denisof, who joined the series in season three as Buffy's new watcher Wesley Wyndam-Pryce and later starred in the Angel spinoff. The couple wed in 2003 and have two daughters.
11. Before falling in love with Denisof, however, Hannigan revealed she did enjoy a little romance with co-star Nicholas Brendon.
"I think Nick and I might have kissed once, like off camera," Hannigan shared during a 2019 appearance on Watch What Happens Live. "He might have had a boob or something."
12. Gellar has a very unfortunate phobia that left her crying hysterically after filming an episode where Buffy was put in a grave. "I have an irrational fear of cemeteries and being buried alive," she told Rolling Stone. "It's really hard to be a vampire slayer if you're scared of cemeteries." (A fake cemetery was later built on the set.)
13. Whedon almost quit the show after he received pushback for Willow's romance with Tara (Amber Benson). Co-executive producer David Greenwalt revealed a phone call he received from a Warner Bros. exec after hearing about the storyline, asking, "Is [Joss] really going to do this gay thing?" When asked to cut the couple's first kiss, Whedon said he threatened to walk. "It's the one time I pulled that out," he said. "And they were like, 'No, it's okay. Leave it in.'"
14. Two near-miss guest stars on the show included Britney Spears, who would've played April the robot in "I Was Made to Love You," and Gellar's real-life love Freddie Prinze Jr. as Dracula in the season five premiere.
15. Whedon's favorite characters to write for included Spike and Andrew (Tom Lenk), with the creator admitting during a 2012 Reddit AMA that Angel was "the hardest…how to make a decent, handsome, stalwart hero interesting—tough."
16. A few storylines Whedon wish he had really driven deeper? "There are a couple of things I would've liked to have seen a little more of; either Vampire or Hyena Xander, because Nick pulls that off really well," he said in an interview with The New York Times. "And I wish we had been able to service Dawn's character a little bit more in her third season."
17. We guess she's done baking: Gellar revealed during a Reddit AMA in 2014 she's Team Angel when it comes to Angel vs. Spike.
18. When asked if she kept anything from the series after it ended, Gellar revealed in the same Q&A that she snagged some of Buffy's clothes in addition to a memento she still keeps close to her.
"I think my favorite is that my makeup artist had made a special stake for me with a little bottle of holy water," she said. "To this day I keep it by my bed."
19. Throughout the show's seven-season run, season four's silent outing "Hush" was the only episode to score a major Emmy nomination when Whedon was recognized for Outstanding Writing for a Drama Series.
20. The season five finale, "The Gift," was initially written to serve as the end of the series, with Buffy ultimately sacrificing herself to save the world. Once the show was picked up by UPN, several ideas were saved for the seventh and final season's ending, including the destruction of Sunnydale.
21. "The Gift" served as Head's final episode as a series regular, with the actor taking on a reduced role in order to spend more time with his family in the U.K.
22. Gellar announced her departure from the series after seven seasons in 2003.
"'You always worry about being the show that's been on too long—especially when you're a cult hit,'' Gellar explained to Entertainment Weekly at the time. ''Last year, a lot of people were ready to tear us down. [So when] we started to have such a strong year this year, I thought: 'This is how I want to go out—on top, at our best.'''
23. The announcement came as a surprise to her co-stars, with Hannigan and Brendon telling EW they found out about Gellar's departure and the show ending from the magazine, "which kind of sucked," Brendon admitted. "That's not the way it should have happened…but everything happens for a reason."
24. At the time, Whedon was developing a spinoff that would have included several of the Buffy stars, telling EW, "It will be a completely different animal," adding that Gellar had promised to make several appearances. The project ultimately never happened. Another potential series that was considered would've have focused on a school for potential slayers.
25. A spinoff centering on badass slayer Faith (Eliza Dushku) was also in the works, but it ultimately fell through. "I had come up with a pitch. Eliza was gracious, kind and wonderful, but she felt like she wanted to do something new," executive producer Tim Minear told IGN in 2003. "There is no hard feelings there. But the show was basically going to be Faith meets Kung Fu."