Brock Lesnar only spent two years in WWE during his initial run with the company, but from 2002-2004 he was The Next Big Thing. Lesnar left WWE to pursue a dream of becoming an NFL star but his attempt at joining the Minnesota Vikings didn't pan out for him.
Lesnar spent some time in New Japan Pro Wrestling where he became IWGP World Heavyweight Champion on October 8, 2005. Lesnar defeated Kazuyuki Fujita and Masahiro Chono in the Tokyo Dome and held the title for 280 days before losing it to Kazuyuki Fujita.
From 2008-2011, Lesnar competed in the UFC's Heavyweight Division. He became UFC Heavyweight champion in November 2008 by defeating Randy Couture and had a successful title defense against Frank Mir before being taken out of action due to diverticulitis.
Lesnar's return to WWE in 2012 resulted in many more stories for him. After feuding with John Cena, Triple H, CM Punk, and The Big Show, Lesnar ended The Undertaker's WrestleMania undefeated streak. The Beast Incarnate went on to defeat Goldberg the following year to become WWE Universal Champion, a title he still holds to this day.
After working such a light schedule, plenty of fans took notice of how often the WWE Universal Champion appears on Raw. His part-time schedule provides WWE the opportunity to book Lesnar as an attraction, but the appeal of UFC has always piqued Lesnar's interest as well.
WWE allowed Lesnar to fight at UFC 200 against Mark Hunt in a match he won, but the result was later overturned after Lesnar failed a drug test. With Lesnar's WWE contract running out, most thought WrestleMania 34 would be his goodbye from the company. He defeated Roman Reigns and retained his Universal Championship instead of leaving. Lesnar signed a short-term contract after that, but it didn't stop the UFC rumors from constantly emerging.
Lesnar retired from UFC in 2017, but if he re-entered the USADA pool he would still need to serve out the remainder of his suspension after his failed drug test.
Lesnar showed up in the crowd during UFC 226 being led by Dana White. He wasn't holding his WWE Universal Championship either.
He took a seat at ringside to watch UFC Heavyweight Champion Stipe Miocic defend his title against Daniel Cormier. WWE's official website also ran a story about Lesnar's attendance at UFC 226 saying to, "stay tuned to WWE.com for any updates on Lesnar's WWE contract."
Cormier defeated Miocic and became the new UFC Heavyweight Champion after a first-round knockout. Now a two-time UFC Heavyweight Champion, Cormier then invited Lesnar into the Octagon with him. Then Lesnar approached DC and shoved him across the ring.
Lesnar grabbed the microphone and cut a promo for himself saying: "I walked into this building and watched the Heavyweight disasters from the beginning...Ngannou's a piece of s--t, Miocic, the piece of s--t, DC...I'm coming for you motherf--ker."
Brock Lesnar has made his intentions quite clear and it appears Cormier and the UFC Heavyweight Title are in his sights. Dana White later commented that he did not know when Lesnar vs DC will happen though.
White: I don't know when for DC vs. Lesnar. #UFC226— MMAFighting.com (@MMAFighting) July 8, 2018