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.