White Fang is a trophy quest in Act III of The Witcher. The Royal Huntsman in Vizima’s Trade Quarter mentions a large wolf called Voref that has been prowling the Swamp Forest and hunting people – the kind of wolf that makes ordinary wolves look like lapdogs.
Voref only comes out between dusk and dawn, and he won’t appear at all while you’re busy rescuing the brickmakers, so pick your timing. Kill him, take his head and bring it back to the Huntsman for the bounty. Bosses like Voref don’t respawn, and you can only carry one trophy at a time, so hand in the Moa trophy from The Predatory Wyvern first if you’re doing both.
