Just because it's obvious doesn't make it any less true. Did Conor McGregor forget that Brock Lesnar is technically a member of the WWE roster? When he said he'd smack the head off the roster, twice on Sundays, he was including Lesnar in his bragging. Good luck with that.
Lesnar stands 6'3", and is 285 pounds. His mixed martial arts record currently stands at 6-3, and the majority of his matches took place while he was dealing with diverticulitis, an absolutely crippling affliction for normal men. He's one of the baddest combat fighters on earth. And yes, he's under the employ of Vince McMahon.
Lesnar brings legitimacy to the WWE, especially when he fought in the UFC while under WWE contract. The spectre of a doping allegation looms large over Lesnar's victory over Mark Hunt, but he still went in the octagon after a multi-year absence and beat a top 10 heavyweight. Lesnar is a bad, bad man and Conor wouldn't stand a chance.