Moose Toys is going all in on goo. The Australian toymaker is launching its new collectibles range Goo Goo Galaxy—which features alien babies with slime-filled bodies—on August 1.

The line targets girls ages six to eight and features four characters with DIY slime activities that see kids mixing ingredients to make unique goo creations. Moose Toys partnered with Instagram and YouTube influencers to tease Goo Goo Galaxy online before debuting the brand at an event at FAO Schwarz in New York. The event  included exclusive early purchases, with the product selling out in two hours.

Goo Goo Galaxy comes hot on the heels of Moose Toys’ most recent slime-related range, Goo JitZu. The action figures are filled with slime that lets their limbs squish and stretch, and are part of an ongoing fascination with all things ooey and gooey. Earlier this year Nickelodeon announced a new pop-up experience dedicated to its famous green slime in Atlanta, Georgia, and Corus Entertainment’s Nelvana is getting in on the trend as the global licensing agent for Monomi Park’s Slime Rancher gaming property.

Moose Toys’ partnership with FAO Schwarz follows the retailer’s recent resurgence. After closing the doors of its famous Fifth Avenue location in 2015, FAO Schwarz returned to the Big Apple late last year, opening a new flagship store on November 16 in Manhattan’s Rockefeller Center. Then, earlier this year, the retailer announced its first-ever European flagship store with a location planned at Selfridges in London.