Former UFC heavyweight champion Brock Lesnar undeniably left a mark on the sport of MMA. After obtaining the NCAA Division wrestling championship in 2000 and going on to win the WWE championship, Lesnar made his UFC debut at UFC 81 in early 2008.

The night will be forever etched in Octagon lore, as Lesnar bull rushed fellow former heavyweight champ Frank Mir to signify he had arrived. Brute strength wasn’t enough, however, as Mir rebounded to pull off a classic kneebar submission.

But that was only the beginning of “The Beast's” run in UFC.

Lesnar beat Heath Herring his next time out, and then won UFC gold by defeating the legendary Randy Couture at UFC 91. From there, Lesnar went on to headline the biggest MMA event of all-time, avenging his previous loss to Mir in a one-sided beatdown at UFC 100.

That was the height of his popularity in MMA, as an unfortunate bout with diverticulitis marred the rest of Lesnar’s short MMA career. Originally scheduled to face Shane Carwin for the belt in November 2009, Lesnar returned at UFC 116 in July 2010 after healing from the ailment.

But it was clear he was never the same, and a new crop of UFC heavyweights had already arrived. A new highlight reel of Lesnar losing emerged after current UFC heavyweight champ Cain Velasquez pounded him in a stumbling defeat at UFC 121. Lesnar fought on, appearing on The Ultimate Fighter (TUF) 13 opposite Junior dos Santos, but was forced to withdraw from the season-ending bout to continue battling diverticulitis.

Lesnar eventually came back at UFC 141 in 2011, but this time, he was on the way out. Eating a vicious body kick from UFC-debuting Alistair Overeem, Lesnar was easily finished in the first round and retired immediately after the loss.

There’s not a single fighter out there that made or will make the impact that Lesnar did with a 5-3 overall record. Many will argue that fighters like Velasquez, dos Santos, and Overeem had simply passed him by in overall skillsets, and they may very well be correct. But there’s no denying “The Beast’s” electric drawing power and impact upon mixed martial arts.

In the above Ultimate Fighting Championship Fight Pass video, Lesnar’s influence is commented on by his WWE peer “Stone Cold” Steve Austin, who said that Lesnar took the UFC by storm. There’s no doubt he did just that. “Stone Cold’s” simple take on Lesnar’s foray into MMA:

“Bottom line is, Brock is a badass cat."

That he was. While it would have been interesting to see how he would have done against the best fighters in the world were he not stricken by diverticulitis, Lesnar’s impact cannot be denied. What is your favorite memory of the brutish former champ?