Currently, nine fighters reside in the UFC Hall of Fame, with Tito Ortiz being the latest inductee earlier this year.
The first time the UFC put guys in the Hall of Fame was in 2003, when Royce Gracie and Ken Shamrock were inducted.
The rest of the members of the UFC Hall of Fame are Randy Couture, Mark Coleman, Matt Hughes, Chuck Liddell, Dan Severn and Charles "Mask" Lewis.
Saturday night, BJ Penn fights at UFC on Fox 5 against Rory MacDonald. Penn is a former two division champion, where he won titles at lightweight and welterweight.
Penn has faced all comers who were in their prime. He has faced Georges St-Pierre, Matt Hughes, Jens Pulver and even fought outside his weight class when he battled Lyoto Machida in Japan.
With those accolades, Penn is a sure-fire UFC Hall of Famer.
Which other fighters are locks to join Penn? Let's take a look.