Calaway was rebranded as "The Undertaker" in the WWF, and gained significant mainstream popularity as a horror-themed, macabre entity who employed scare tactics and held links to the supernatural. The longest-tenured wrestler in company history at 30 years, The Undertaker was one of the most prominent figures of the Attitude Era, a boom period in the company's business in the latter 1990s. His character transitioned into a biker in the early 2000s, before returning to a refined version of his previous gimmick in 2004. The Undertaker is heavily associated with WWE's flagship annual event, WrestleMania, where he became known for The Streak, a series of 21 straight victories. He is also known for his pairing with his in-storyline half-brother Kane, with whom he has alternatively feuded or teamed as The Brothers of Destruction since 1997. Within the company, The Undertaker has won the WWF/E Championship four times, the World Heavyweight Championship three times, the Hardcore Championship once and the World Tag Team Championship six times. He is also one of WWE's most prolific pay-per-view performers, headlining several pay-per-view events, including WrestleMania on five occasions.