Elisha Dushku grew up Mormon and refused to do nude scenes on the show. She was also a minor at the time and had to receive emancipation to work the long hours of the show. She said the judge was a fan of Buffy and signed the order on the condition he could get an autographed photo of Dushku.

After Warren kills Tara, Willow turns into a dark sorcerer and hunts him down. She magically inflicts the pain of Tara's death on him by forcing a bullet through his chest. He begs for mercy and she sews his lips shut by magic, then kills him by flaying and incinerating him.

Whedon and several crew members referred to Gellar as Jimmy Stewart because of the pain she would endure while filming. Whedon said, "We used to call her Jimmy Stewart, because he was the greatest American in pain in the history of film."

"Passion is the source of our finest moments. The joy of love...the clarity of hatred...the ecstasy of grief. It hurts sometimes more than we can bear. If we could live without passion, maybe we'd know some kind of peace. But we would be hollow. Empty rooms, shuttered and dank. Without passion, we'd be truly dead."

Although originally a human member of the Initiative, after he died, Professor Walsh used his body for an experiment to create a super soldier. He bacame Adam, who was part human, part demon, and part robot.

After discovering a human finger in the meat grinder, Buffy thinks the secret ingredient is human meat. She later discovers that body parts are showing up at the restaurant due to a demonic being feeding on the employees and the secret ingredient in the Doublemeat Medley is just processed vegetables.

Most of the cast didn't know the series was ending until Sarah Michelle Gellar revealed in an Entertainment Weekly interview that she was leaving the show.

After Tara's death, Willow becomes a dark magician that plans to end her pain by ending the world. After an unsuccessful physical confrontation, Xander reminds Willow of his love for her and tells her he will stay with her until she destroys him in her quest to end the world. He eventually breaks down her barriers and her dark powers drain away.

Throughout the series, Anya has leporiphobia, a fear of rabbits. When told to wear something "scary" to a Halloween party, she appears dressed in a bunny costume, and her phobia becomes a running joke for the remainder of the series.

In the final episode, the entire town of Sunnydale collapses into the Hellmouth cavern, leaving a large crater where the town had been.