Former UF C champion Cain Velasquez formally announced his arrival in the WWE recently and immediately took aim at an old nemesis - Brock Lesnar. The 37-year-old mixed martial artist hinted as early as July that he was looking forward to making his pro wrestling debut.

That all materialized on the October 4 edition of WWE SmackDown, making an appearance alongside Rey Mysterio after The Beast annihilated Kofi Kingston in just seven seconds to win the WWE title. However, Velasquez spoiled any planned celebration with the American mixed martial artist wasting no time to go after The Beast.

Velasquez unloaded with a double leg takedown and landed several strikes on the former WWE champion. This forced Lesnar and Heyman to retreat, both seemingly appearing as if they had seen a ghost.

Lesnar lost to Velasquez at UFC 121 on Oct. 23, 2010 via technical knockout in the first round. The Beast would announce his first retirement afterwards as he battled diverticulitis. He would return at UFC 141 against Alistair Overeem where he again lost via KO in the first round. The Beast Incarnate would move to the WWE although he appeared one last time in the Octagon.

Lesnar's last appearance in the cage was at UFC 200, initially winning over Mark Hunt. However, the result was overturned when it was found that The Beast tested tested positive twice for clomiphene and was subsequently suspended, MMAFighting.com reported.

Since returning to the WWE, Lesnar has been seemingly unfazed with the competition. He has portrayed a cocky and dominant attitude although he has lost to several wrestling stars such as Bill Goldberg, Roman Reigns and Seth Rollins. Now, he faces an old nemesis where scores need to be settled.

But if the way Lesnar and Heyman looked at WWE SmackDown is any indication, the upcoming showdown between the two behemoths in Saudi Arabia should be an interesting one. For the first time in a long while, odds could be tilted in the favor of Lesnar's opponent.

The arrival of Velasquez is only one of several fight sports personalities invading the WWE. Frank Mir made his debut at Wrestlemania 35. Like Velasquez, the 40-year-old mixed martial artist also has his eyes set on Lesnar.

The other fighter trying out the WWE is boxing champion Tyson Fury. But unlike Velasquez and Mir, it seems he has a script brewing with The Monster Among Men, Braun Strowman.

Cain Velasquez 2015 UFC heavyweight champ Cain Velasquez, right, steps into the octagon for the first time in nearly two years versus Fabricio Werdum Saturday at UFC 188 in Mexico City. Photo: Reuters