Shark Tank: Kevin O'Leary's 'Mr. Wonderful' Nickname Explained

Now in its 15th season, "Shark Tank" continues to attract viewers with its gameshow-like approach to the entrepreneurial climb to the top. Every reality series — even one rooted in finance — needs a villain, and for "Shark Tank," that person is Kevin O'Leary. The Canadian businessman brings a fiery bite to the series, often fanning the flames of shark-on-shark disputes and offering a tough-love approach to business. It makes sense, then, that his nickname, Mr. Wonderful, came from a place of sarcasm.

In an interview with Boston Magazine, O'Leary clarified where his infamous nickname came from, claiming that even the sharks struggled to recall its origins. "We are all trying to figure that out," said O'Leary, who confirmed that the nickname was born in the tank. "This is what seems to be consensus now: In season one, someone was trying to sell a publishing deal to us for music and I proposed an aggressive 51 percent equity position because I wanted control of the business. And Barbara [Corcoran] said, 'Well aren't you Mr. Wonderful?' and I said, 'You know what Barbara, I am!'" O'Leary added that the nickname has taken on a life of its own. "Now it's at a whole new level," he continued. "I show up at hotels and my reservation is under the name Mr. Wonderful. They don't even know my real name. That's just nuts."

Mr. Wonderful may have started as some gentle ribbing from fellow shark Barbara Corcoran, but Kevin O'Leary has wholeheartedly embraced the nickname. He even named his holding company, through which he manages all of his "Shark Tank" investments, Something Wonderful.

For O'Leary, Mr. Wonderful is an exercise in personal branding, and he has infused it with a certain amount of lore. "The reason they call me Mr. Wonderful is because I have the most creativity in structuring deals," O'Leary told Forbes, conveniently leaving out the anecdote about Corcoran. He then went in for the kill, embracing his status as the big bad shark. "The other sharks are very boring. It's the same thing over and over again: $100,000 for 10% equity. How boring! And how uncreative! That's why they learn from me. They're very lucky up there."

Still, it's clear that Mr. Wonderful is mostly a marketing facade or fewer "Shark Tank" contestants would be willing to make a deal with him. When Wicked Good Cupcakes founders Tracey Noonan and Danielle Desroches teamed up with O'Leary, they were worried about his reputation. Behind the scenes, however, they called him "an angel in disguise" as well as "a tremendous mentor" while speaking to Business Insider. Insofar as business partners go, it sounds pretty wonderful.