Donald Jacob Hager Jr. is an American professional wrestler and mixed martial artist, currently signed to All Elite Wrestling (AEW) under the ring name Jake Hager. Hager is also known for his time in WWE under the ring name Jack Swagger. As a mixed martial artist, he is currently signed to Bellator MMA where he competes in the heavyweight division. Hager attended the University of Oklahoma as a two-sport athlete, participating in both football and wrestling. He switched to wrestling full-time in his sophomore year, and in 2006, set the record for most pins in a season with 30 as an All-American. Following a try-out, Hager signed a WWE contract in mid 2006 where he performed as "Jack Swagger". During his time with WWE, he became a two-time world champion, having held the WWE's World Heavyweight Championship and the ECW Championship once each and a one-time United States Champion. He left the company in 2017 after he decided to pursue a professional mixed martial arts (MMA) career. In 2017, Hager signed with Bellator MMA. He had his first professional fight on January 26, 2019 against J.W. Kiser at Bellator 214, where he won via arm-triangle choke in the first round. In his second fight with the promotion, he faced T.J. Jones on May 11, 2019 at Bellator 221, where he again won via arm-triangle choke in the first round. He is currently undefeated with a record of 3–0 (1). As a wrestler, he kept working with various promotions before signing with AEW in 2019, including in Lucha Underground as Jake Strong, where he was the final Lucha Underground Champion. He is the only man in history to have been ECW, (WWE) World and Lucha Underground Champion.[citation needed] Hager, in total, is a four-time world champion in professional wrestling.