William Taurens ne pensait jamais qu'en essayant le serum de Monsieur Klein, il se transformerait non seulement en homme fort, mais éventuellement en homme taureau ! William Taurens started his criminal career in adolescence when he was arrested for petty theft. When Daredevil was on his trail, he was a guinea pig for Mister Klein and his serum made from bulls, intended to make super strong criminals. It worked too well, eventially transforming him in a human bull.