Werewolf in Oblivion (Xbox 360): Not Possible — Play Skyrim

You cannot become a werewolf in The Elder Scrolls IV: Oblivion on any platform. Lycanthropy as a playable mechanic was introduced in The Elder Scrolls V: Skyrim (Companions questline / Dawnguard DLC for Vampire Lord).

Oblivion's Beast Options

• Playable Races: Khajiit (feline), Argonian (reptilian) — cosmetic + racial bonuses (night eye, water breathing, unarmed damage).
• Vampirism: Contract Porphyric Hemophilia → feed/sleep to stage up. Sun damage, stat boosts, powers (Charm, Night Eye, Invisibility). Cure via "Vampire Cure" quest.
• Shivering Isles DLC: "Beast Form" spell (Sheogorath's quest) — temporary wolf-like combat form. Not true lycanthropy.
• Mods (PC Only): Werewolf Mastery, Better Werewolves ports — require OBSE, not on Xbox 360.

Skyrim: The Werewolf Experience

• Join Companions (Whiterun) → complete questline → ritual in Underforge.
• Beast Form: 2.5 min duration, 100% disease immunity, howl, claw attacks, feeding on corpses extends time.
• Dawnguard DLC: Werewolf Perk Tree (totems, fear howl, summon wolves).
• Vampire Lord (Dawnguard) alternative.

If you want to howl at the moons, buy Skyrim Special Edition (Xbox One/Series, PS4/5, PC) — it's the definitive way.