Most such imagery is drawn from classical mythology, with the most popular being from Greek/Roman lore. But fairy tales, particularly those chronicled by the Brothers Grimm, are an endless source of inspiration for modern storytellers. They were, after all, stories designed to teach harsh life lessons to the youth of those times, and that's something Joss Whedon did in spades throughout Buffy's run, especially in the early "high school is Hell" years.
One such fable that appears to be strong inspiration for the main season 2 arc would be Little Red Riding Hood. We all know the story: girl is told to bring gifts to her sick grandmother, encounters a wolf on the way there, said wolf later devours both girl and grandmother whole before a brave huntsman comes along and cuts them out, killing the wolf, yay. But few modern audiences know that there are much earlier versions of the tale that were far less sanitized and far more gruesome than modern iterations.
Neil Gaiman presented one such telling in his classic the Sandman series, issue #14, part 5 of "the Doll's House" storyline. I'm going to avoid getting into the specifics of that storyline to prevent spoilers, but this issue depicts one character telling a young girl a much darker take of Little Red's encounter with the Wolf. In it, the Wolf doesn't eat the grandmother himself, but instead chops her into pieces before dressing in her clothes. Pretending to be the grandmother, the wolf tricks Red into eating the "meat" before casting all of her clothes into the raging fireplace. He then commands the girl to climb into bed naked with Nana. The usual "what big teeth/eyes/holy-shit-that's-a-lot-of-fur/e
The end. No, seriously, that's it. No huntsman to bail her out at the last minute, that girl is a toast. NOW GO TO SLEEP CHILDREN.
The Freudian implications of this telling are pretty intense. The tale, particularly versions such as this, has often been cited as a warning to young girls to avoid sexual predators. It's no coincidence that the wolf commands her to undress before he "devours her" in a bed of all places. The color of her cloak is also symbolic of the girl's menstrual cycle, often thought to be her first, which is tied to her approaching transition into a woman (and, thus, ready for sex).
Longtime fans of Buffy's zany adventures are familiar with the term "Big Bad," often used to describe the primary villain for each individual season arc. But while the term has taken on a life of it's own, and been applied to every major villain in the series (and extends over to Angel, and practically every show that follows a similar formula), it was first used in a season 2 episode to describe Angelus. Thus, despite the fact that the term was retroactively applied to the Master to define his role for season 1, Angelus is the original Big Bad of the series. And while it has never been confirmed, it has often been theorized that Buffy was using it as a shortened reference to the Big Bad Wolf of the fairy tales.
Considering the major storyline revolving around Buffy and Angel for the season, it's not surprising that Whedon would draw inspiration from Little Red Riding Hood, paying particular attention to the sexual undercurrents in her interactions with the Wolf.
It's no secret that there is some sexual predator imagery tied with Angel in his early interactions with Buffy. It is not his actual character or his intentions, but merely one aspect in his metaphorical role in the season. Angel had nothing but pure intentions when he was first assigned to protect Buffy, and his love for her was genuine. But there are parallels drawn between him and Tom, leader of the frat boys in the otherwise forgettable episode "Reptile Boy." The frat boys symbolize vampires as a whole, with Tom "being the one to watch out for" because he is seemingly nicer than the others. And that's to say nothing of his first observation of her being from a sketchy looking car, looking all grungy and staring at her while she sits on the school steps. There's also Angie Hart's song "Blue" at the beginning of "Conversations With Dead People," a song which Whedon co-wrote the lyrics to. The song is often thought to be about Buffy's relationships with Angel, Riley, Spike and Willow's resurrection of her. The verse "Tight skin/wolf grin" is often cited as being about her romance with Angel, and his turning into a demonic incarnation.
Considering Angel continues to love Buffy after she reaches her mid-20's, and every other woman he shows interest in is a grown adult, we can safely conclude he isn't a creep who lusts after teenagers. No, this was Whedon's best executed melding of metaphor, story and character without sacrificing any one element to advance the others (*coughseason8cough*). Angel is cast as a villain, but in such a way that his role as a potential hero and love interest isn't compromised. Indeed, the role of the Wolf can be more specifically assigned to his Angelus incarnation. Arguably, his role as Red Riding Hood/Buffy's protector solidifies ensouled Angel as the Huntsman in this scenario.
And that's where Buffy comes in to do what she does best: subvert tradition. In Whedon's tale, it is the Huntsman, not Riding Hood, who is consumed by the Wolf and seemingly lost. Red Riding Hood saves herself from the Wolf; and while Willow is the one to restore Angel's soul, it is Buffy who later helps pick Angel off his feet and get him started on his mission of redemption. Riding Hood not only saved herself, but inspired the Huntsman to save himself as well, and to go on to save others.
I may not always like everything Joss creates, but he will forever have my admiration for creating such a kickass, subversive heroic figure in Buffy.