Previously on Buffy: Oz comments on a cheerleading trophy, saying that its eyes seem to follow you around. That's because Amy's mother, a witch, was trapped in it in the episode The Witch.

Xander refers to a hyena possession he underwent in the The Pack, shutting up quickly when he's reminded that he claimed not to remember anything he did during it.

When Buffy blames herself for Theresa's death, Xander refers in quick sucession to I Robot, You Jane ("Willow would be Robbie the Robot's love-slave") and Teacher's Pet ("I wouldn't even have a head.")

A weight off his chest: Once he's accidentally forced out of the closet by Xander, Larry's admission that he is gay comes as a great relief to him. And to everyone else, as at last he stops acting like a male chauvinist pig.

The first gay character in the series, he started a trend for positive and unsensational portrayal of homosexual characters in Buffy which continued with the love affair between Willow and Tara from season four onwards.

Hairy homage: Phases draws heavily on a great many classic old werewolf movies, such as 1941 horror The Wolf Man with Lon Chaney Jr, The Howling (1980) and An American Werewolf in London (1981). Then there's also the 1985 comedy Teen Wolf, in which Michael J Fox discovers that lycanthropy can make you more popular at school. Well, Oz is a teenage werewolf too, isn't he?

33 days has September: Pointing out that the werewolf is a normal person, probably unaware of his full-moon murders, Buffy seems to feel that a lunar month lasts 31 days. "And it doesn't bother you that a werewolf is a person the other 28 days of the month?" she demands of hunter Cain. I think you'll find that's 25 - there are 13 lunar months of 28 days each per year, with the moon being full for three days out of each one.

Freaky fragrance: "I think you splashed on a bit too much Obsession for Dorks," snips Cordelia while Xander frets over Oz's interest in Willow. It's a reference to the famous Calvin Klein perfume - Obsession for Men/Women.

Moon music: The band playing in the Bronze when the werewolf attacks is Lotion, performing the song Blind for Now.

Hone those muscles: "Thank you, Thigh Master," says Larry, after taking an unwelcomed peek up a girl's skirt. A piece of home exercise kit, Thigh Masters consist of a number of foam-covered springs which are squeezed between the legs, hopefully leading to "toned outer thighs and shaplier buttocks."

Like a big pizza pie: The moon may bring out our darkest qualities, according to Giles, but Xander points out that at least it led to the invention of the Moon Pie. For those unfamiliar with this piece of US confectionery, a Moon Pie is a round, marshmallow filled biscuit, covered with chocolate.

The story goes that it was invented when a Mr Mitchell asked some miners what they'd appreciate as a lunchtime snack. They answered that it had to to be solid and filling. When asked how big it should be, one of the miners held out his hands, framing the moon which was just rising then, and said "About that big." Mr Mitchell later combined local bakery delicacies into an item just that big, and called it the Moon Pie.

Familiar face: Jack Conley, who played Cain, should be familiar to anyone who's seen Angel season three, in which he plays the enigmatic Sahjhan. He's also appeared in cult shows Dark Skies and Freaks and Geeks.

Oooh, Missus: There's a treat for the ladies, and Larrys, in this episode - an eyeful of buck naked Oz. Now that's a sight for sore eyes. But does he have strange tastes or something? Where did all those shackles come from?