At 28-years-old, Conor McGregor has made a name for himself in the MMA world as one of the most transcendent athletes to ever participate in the sport.

Holding a career 21-3 record, including 18 KO/TKOs, the Irishman has not only been a force in the ring, but has been a personality outside of it, showing off his eccentric personality and arguably serving as the face of the sport over the past few years.

In the past year, McGregor’s superstardom grew even more when he knocked out former lightweight champion Eddie Alvarez in UFC 205 at Madison Square Garden, becoming the UFC’s first ever multi-division simultaneous belt holder. Prior to that, he earned a featherweight belt when he took down longtime champion Jose Aldo in a 13-second knockout.

Recently, his name has been linked to serious talks of a boxing match with Floyd Mayweather, which would be one of the must-see sporting events in recent memory.

As a result of his growing popularity and rockstar status within the fighting community, Time Magazine named him to their 100 Most Influential People list.

Placed into the “pioneers” category, he joined other sports stars like LeBron James, Tom Brady and Neymar. Ronda Rousey was the last UFC athlete to make the list, appearing on last year’s edition.

Arnold Schwarzenegger is a huge MMA fan and a self-described fan of “The Notorious”. He was tasked with writing McGregor’s profile on the list, and did his best to explain how his talents extend outside of the octagon:

“Conor McGregor is more than a fighter, more than an athlete, more than a champion—although, as the first person in the history of the Ultimate Fighting Championship to hold titles in two weight divisions at once, he is clearly all of those things,” Schwarzenegger wrote. “Conor is also the rare personality who has become bigger than his sport. That lean, compact body must struggle to keep his enormous character inside.”

He continued, “From the first time I met Conor, I knew he wasn’t the type of star you could box into one category. Since I’ve gotten to know him, I can tell you that what you see on the screen—the now familiar face of mixed martial arts—just scratches the surface. The Dublin native is razor-sharp, disciplined and charismatic. His energy is absolutely contagious, to the point where you almost start shouting in an Irish accent after 30 seconds of hearing that world-famous mouth.

Finally, “The Terminator” actor and former California governor summed up McGregor’s never-ending desire to dominate, saying, “Conor has a fire in his belly that can’t be quenched with championship belts. There are no brakes that can stop his engine.”

It has been reported that the purse in a Mayweather/McGregor boxing match might land the Irishman upwards of $75 million. While taking down the undefeated boxer in a completely new sport might seem like a daunting task, it seems like McGregor might have what it takes to at least make it tough on his opponent.