Billionaire investor Mark Cuban may be brash, but it's not always outspoken entrepreneurs who impress him--it's those who hustle the most.

Benjamin Stern, a 16-year-old from Melbourne, Florida, wowed all the Sharks on Friday's episode of Shark Tank with the pitch for his eco-friendly shampoo company, Nohbo. But it was Dallas Mavericks owner Mark Cuban who was most impressed with the soft-spoken Stern.

"I love it, absolutely love it," Cuban said. "You remind me of me when I was younger." 

Stern fielded plenty of deals but decided to partner with Cuban, who called Stern his "Mini-Me" and offered to invest $100,000 in Nohbo in exchange for 25 percent of the company.

So why the feeding frenzy over a company run by a teenager? While Stern may not have a lot of experience, his work ethic rivals that of some of the adult entrepreneurs that have appeared on the show. When he was 7, he used to buy a box of cookies from Costco and spend the afternoon selling to passersby at the mall. 

"He was constantly testing ideas and asking me, 'What do you think of this idea?'" Stern's mother, Carrie Warren, says. "But then he would find that product that he wanted to develop was already in stores."

He came up with the idea for Nohbo after he watched a documentary in biology class about how damaging plastic bottles can be to the environment. He wanted to find a way to cut down on the number of bottles Americans throw away, so he created a shampoo ball that uses a compostable wrapper instead of plastic. 

"Ben really did everything on his own," says Warren. "He found everything--he even found the chemist [who developed the Nohbo ball]."

Finally, Stern had come up with an idea that he could turn into an original product--and the Sharks were impressed.

"This could be one of the best things I've seen on Shark Tank," declared Robert Herjavec.

Though Nohbo is still waiting for its patent and has yet to sell a single product, Stern said he got a part-time job to pay for some of Nohbo's initial expenses and cold-emailed Clorox and Hyatt Hotels, among other companies, to pitch them. That elicited applause from Cuban. 

"That would be the most intimidating thing for even a grownup," said Barbara Corcoran, who gave him an offer, along with Herjavec. 

Next on the teenager's to-do list is an Indiegogo campaign and developing a sunscreen and a shaving-cream ball. 

"It's definitely the coolest thing I've ever done," Stern said. "The feedback we've received on Nohbo is amazing. We've gotten over 20 investment offers so far."