Olympian Kayla Harrison Says MMA Fighters Are Afraid of Me

U.S. Olympic legend Kayla Harrison -- who won gold in judo in '12 and '16 -- is finally making her MMA debut this week ... and says she's ready to wreck shop.

Kayla is a beast -- and she tells TMZ Sports it was hard to even lock down an opponent because people are scared to fight her.

The good news ... Brittney Elkin has stepped up and will fight Kayla at the PFL event in Chicago on Thursday, and Kayla tells us she can't wait to scrap.

"I have 500 judo matches under my belt," Kayla said ... "I have some experience -- just not with a locked cage behind me."

So, how will she handle taking a live punch to the face for the first time?

"I'm kind of a bull. It's gonna take a lot more than 1 punch to take me down."