What is the name of Willow's werewolf boyfriend? His name is Oz.
Oz, whose full name is Daniel Osbourne, is a quiet guitarist and student who becomes Willow Rosenberg's boyfriend in Buffy the Vampire Slayer. He is played by Seth Green and first appears in the second-season episode “Inca Mummy Girl,” where he performs with his band at the Bronze.
Oz later discovers that he is a werewolf after being bitten by his cousin Jordy. The transformation initially occurs around the full moon, forcing him to lock himself in a cage so that he cannot hurt anyone. Willow accepts the frightening revelation, and their relationship becomes one of the show's more unusual romances.
Viewers sometimes confuse Oz with other Buffy love interests. Riley Finn dates Buffy, Xander Harris is Willow's longtime friend, and Spike is a vampire who becomes an uneasy ally. Oz leaves Sunnydale during the fourth season to learn how to control his werewolf nature, later returning with much greater control over his transformations.