Rener Gracie is MMA royalty -- a member of the legendary Gracie family which created Brazilian jiu-jitsu.
But, he's also a fashion designer -- and he tells TMZ Sports his business went CRAZY a few weeks ago when he made a deal on "Shark Tank."
Rener is the creator of Quikflip -- which started as a hoodie that transforms into a wearable backpack.
The 35-year-old martial artist was a hit on "Shark Tank" -- and ended up making a $500,000 deal with Lori Grenier.