The 54-year-old boxing legend has teamed up with Discovery Channel for an August 9 special called, "Tyson Vs. Jaws: Rumble on the Reef."

So, what's the show? Seems Mike will "train" with a shark?!! Here's the show description from Discovery ...

"With famed ring announcer Michael Buffer calling the shots, these two heavyweights will square off underwater, where Mike Tyson will try to score a TKO over the massive shark ... all in the name of research."

He adds, "Someone's gonna get bit!"

Again, not really sure what that means -- BUT, WE'RE HERE FOR IT!

"I took on this challenger to overcome fears I still deal with in life," Tyson says in a statement.

"I equate this with overcoming my fear of getting back into the ring at 54 years old. I learned from this experience doing Shark Week that whatever intimidates me, I am still able to step up to the challenge of overcoming anything that would prevent me from accomplishing my life’s mission of reaching my highest potential in life and bringing me closer to God."

As we previously reported, Tyson hit the beach in L.A. a few weeks ago to shoot the spot -- and looked like a BEAST as he tossed around a steel cage, like it was a toy.