This toy has a daily chance to drop from a rare of the same name - Borr-Geth, a Rare Elite located around the Zovaal's Cauldron area in The Maw. Following it's predecessors, this item shoots you in the air, allowing you to glide around the Maw for a short duration when coupled with a glider item such as Goblin Glider Kit. This toy can only be used within The Maw. Unlike Aviana's Feather, you do need to have a glider effect ready to use, or you'll just fall right back on the ground. Currently the toy has a 20-minute cooldown.
Here you can buy Borr-Geth's Fiery Brimstone Toy Boost for EU or US Servers.
You'll get guide for completing Borr-Geth's Fiery Brimstone Toy Boost