Oz

Daniel "Oz" Osbourne is a fictional character created by Joss Whedon for the television series Buffy the Vampire Slayer.The character is portrayed by Seth Green.Green also portrays the character in one episode of the spin-off series Angel. In Buffy, Oz is portrayed as a taciturn, guitar-playing teen who becomes boyfriend to Willow (Alyson Hannigan), one of the show's main characters.After first appearing in the episode "Inca Mummy Girl", Oz discovers he is a werewolf in the episode "Phases" and becomes a recurring character throughout the second season.Green is elevated to main cast for the third season, and departs from the series in season four.Green portrays the character for a final time in the season four finale "Restless" as part of a dream sequence.The character made a brief canonical 'return', however, in the 2009 Buffy the Vampire Slayer Season Eight storyline "Retreat".