The most prominently featured werewolf in Buffy the Vampire Slayer is Oz. He's Willow's, like, mega ironic boyfriend from season 2 and 3.
The episode we're introduced to werewolves is s2 ep15 "Phases." Dominant themes of the episode are masculinity and sexuality. Almost all the male characters partake in sexist subplots that exemplify the toxicities of hypermasculinity: Xander is obsessed with bashing Oz despite the fact that he's in a situationship with Cordy, not Willow; that gay guy is overcompensating by sexually harassing women in public; the werewolf poacher reads retroactively like a stand in for anti-woke twitter culture; and Angelus is like a degenerate older ex-boyfriend who won't stop texting Buffy when he's horny. The episode also flirts with sexuality as a theme in a more general way. The werewolf is attracted to sexual environments (like the kissing-spot and the Bronze), Willow is having trouble getting Oz to kiss her...Oz is going through "changes." Need I say more? Lycanthropy is, at a surface level, very clearly linked to sexual repression. Y'know, like, feeling like you have, like, a creature inside of you that isn't really you or something and it's shameful and must be kept a secret. That's basically Oz this episode. I think he acts as another example of masculinity; he's sort of like a foal to the hypersexual male characters he's surrounded by. But also, I think that if you look at the scope of Oz's character, his lycanthropy could more broadly read as a fear of intimacy in all settings, not just physical. Since he's this kind of stoic, overly ironic, detached character that (we later on find out) has a lot of existential thoughts, it makes sense that he would have a deep fear of vulnerability.
The next episode centered around Oz's lycanthropy is s3 e4 "Beauty and the Beasts." It's similar to "Phases" in that masculinity is a central theme (though this time within the narrower context of domestic abuse) and, once again, there are multiple characters that express different ways of 'doing' gender; this time it's Angel and the freaky Dr. Jekyll knock-off. Angel is back from the dead and got some sort of amnesia but, regardless, he remembers and is aggressively protective of Buffy. Jekyll-boy is an abuser (though perhaps not entirely by choice? since he's shown drinking a flourescent liquid that's never mentioned again --a question for Whedon, I guess). I think there is a vague parallel between the two: they both lost/feared losing someone (Angel lost Buffy, the boy was afraid that his girlfriend would leave him) and their appearences don't reflect their 'true' natures (Angel seems off his rocker but ends up saving Buffy; the other guy seems normal but ends up being the worst). Where does Oz fit into this? It's somewhat unclear. For the first bit of the episode, the gang mistakenly assume that he killed Jekyll's victims while transformed, which sort of strengthens the connection between aggressive masculinity and the symbol of the werewolf. But we don't really get a ton of Oz's perspective on the matter (other than a couple scenes of him being like "whoa guys this is a lot," delivered in that Seth Green monotonality). Ultimately, I think this episode (while Oz centric) does more to define Angel than anything. Boo!