Hundreds of fighters have strapped on the leather and stepped inside the Octagon, but only two men have won titles in multiple weight classes.
That's why former champions Randy Couture and BJ Penn are not only UFC legends, but mixed martial arts trailblazers.
However, as prolific and memorable as their respective runs were, they will not be the last men to ever accomplish this staggering feat.
As of today, MMA's evolution has developed a key pool of athletes capable of stringing together perennial success.
Do these athletes have what it takes to capture divisional titles at two separate levels?
Here are seven fighters who could eventually keep Couture and Penn company in one of the most illustrious clubs around.