Fullscreen, the big YouTube multi-channel network and talent-management group, has bought Austin-based online pioneer Rooster Teeth, home of the hugely popular online video series Red Vs. Blue and other titles predating even the rise of YouTube, the companies announced this morning.

Terms were not disclosed in the deal, the latest in a flurry of acquisitions and stake purchases, mostly driven by traditional media companies in the U.S. and Europe seeking a foothold in the fast-growing online-video space that is centered on young creative talent posting shorts on YouTube (and increasingly elsewhere). The most successful of the creators are building audiences of millions of subscribers, and now are branching out in other directions.

Indeed, Fullscreen itself is an example of this. It was acquired by AT&T and the Chernin Group earlier this fall, and now will use the Rooster Teeth acquisition to hasten its expansion into areas such as premium (read that as “subscription”) content, merchandise and live events, all areas where Rooster Teeth has been an early and hugely successful pioneer.

“Rooster Teeth is one of the strongest and most authentic media brands in the world amongst 18- to 34-year-old, male-skewing audiences,” said George Strompolos, Fullscreen’s CEO and founder. “The combination of its massive reach, unique creative voice and insanely powerful community makes it a perfect match for Fullscreen.”

Rooster Teeth was founded in 2003 and is headed by Matt Hullum and Burnie Burns. The digital production company first made its mark with Red Vs. Blue, a very funny and long-running animated series that spoofs many of the tropes and memes of online videogames, set in a world roughly connected with the hugely popular Halo franchise. It first appeared online even before YouTube launched, and later was made available through DVD and other more-traditional distribution outlets. Other Rooster Teeth series include Achievement Hunter, Immersion, RWBY, and The Gauntlet.

“At Rooster Teeth, we have a long history of creating the best digital content in the industry,” said Burns, Rooster Teeth’s creative director. “With Fullscreen, we look forward to continuing that tradition in even bigger and better ways. Matt and I are excited about the opportunities this alliance will present for our creators and all the amazing content it will empower them to produce for our audience.”

Rooster Teeth also is producing the Indiegogo-financed feature Lazer Team (it raised $2.5 million there; the picture at left is an Indiegogo presentation last summer to Rooster Teeth for setting a fundraising record).

Other operations include a big licensed-merchandise operation, a large network of podcasts and its own multi-channel network with more than 16 million subscribers (the Rooster Teeth channel alone has 7.9 million subscribers). Each summer, Rooster Teeth holds the massive RTX live gathering in Austin, which this year attracted more than 30,000 attendees. It also has a successful subscription-based distribution business, and just launched an ad-supported mobile app carrying some of its biggest shows.

The gaming and lifestyle focus of Rooster Teeth’s YouTube programming will be integrated into Fullscreen’s technology and advertising operations. Rooster Teeth will continue to operate out of Austin, with Hullum as CEO and Burns as creative director.

Fullscreen’s multi-channel network includes more than 50,000 creators. It also has a talent-management unit working with several dozen of YouTube’s most successful creators to expand their reach into traditional media, live events and other opportunities. In September, Fullscreen hosted its first InTour live event in Pasadena.

Rooster Teeth just posted this trailer below for its new animated comedy series, X-Ray & Vav, which launches Nov. 27: