Before its branding birth, the Beast was busy biting the ball in prestigious junior tournaments, building an online following and sending swarms of speculative stringers, players and gear heads into debate over its secret identity.

The Beast breaks out of the box today.

Wrapped around a reptilian eye in a black package devoid of a brand name, the neon green polyester string began generating buzz at junior competitions. Both boys’ finalists at the Eddie Herr tournament played with it. A mystery internet marketing campaign gave 1,300 registered members (of website 361nation.com) from more than 50 nations free string samples. But the identity of the manufacturer that spawned the string remained a source of disagreement among players and stringers.

Until today.

The Beast XP has been unleashed, as Prince officially takes ownership of the string it spent the past 18 months developing, play-testing and promoting through a creative, cryptic marketing campaign intentionally designed to keep the parent company shrouded in secrecy. Prince flips the switch on a new web site, www.beastxp.com, this morning.

The font and graphics of the packaging, which recall both a string bed and a beastly scratch, play on Prince’s aim to position the string as aggressive, edgy polyester. While the move may not be quite as dramatic as seeing Frankenstein rise from a slab in the lab, execs believe the Beast is a “game changer” for the brand.

“We’ve created a monster,” says Sam Cook, Prince general manager of North America. “We’ve created a polyester string we believe is a performance game changer. It’s exciting because we’ve put a stake in the ground in what is an important and dominant category of strings.”

Prince touts the Beast XP as “the world’s first thermo-polymer string” and asserts that its heating and stretching manufacturing process give the string unmatched resiliency and performance.

“We used high-speed military equipment to analyze ball trajectories, rebound velocities, spin rates and impact angles,” Prince vice president of global product management Steve Davis says. “Typically, polyester string loses tension quickly. We’ve used a special manufacturing process of sequential heating and stretching, aligning the polymer chains to ensure the consistency of string tension is maintained, and we’ve added a secret additive we don’t disclose. The result is a string our tests show provides 9 percent more spin than any other polyester string we’ve tested while significantly reducing fliers that land long.”

Though Prince says former world No. 1 Juan Carlos Ferrero, David Ferrer and Galo Blanco play-tested the string, it primarily focused testing and marketing on juniors and recreational players, using the feedback from them to refine the product.

“We’ve created a sense of community among users by incorporating their feedback into development of the string; giving players a stake in it,” says Cook. “It’s an outside-the-box approach we haven’t previously seen in the industry.”

Recognizing its reputation in the polyester market was not on par with giants Luxilon and Babolat, Prince opted to seed the new string in a green wave of anonymity by stripping it of branding in an effort to eliminate any pre-conceived notion players might have of the company. Unbranded samples were handed out at junior tournaments, including Kalamazoo and Eddie Herr. Prince also worked with the IMG Nick Bollettieri Tennis Academy and top online retailers Tennis Warehouse, Tennis Express, Holabird and Midwest Sports to put free samples into the hands of polyester players.

“We wanted to give players a sense of empowerment with this string by saying, ‘We’re not going to tell you who makes it, because we want you to focus on the performance of the string and not the name on the package,’ Davis says. ‘Intentionally, we put little information on the package. Our goal was to reach the polyester-playing addicts by creating a control string that generates more spin, is excellent on tension retention and is comfortable, and our testing shows we’ve achieved that with the Beast XP.”

Prince’s pointed, cryptic approach subverted traditional tennis marketing measures in that the brand bypassed media middlemen and zeroed in on the competitive junior tennis circuit. It was a calculated risk; Prince execs say they did not even inform their U.S. sales staff that the Bordentown, N.J.-based brand was the brains behind the Beast until last week.

MSRP for the Beast XP is $15 per package.