We expect to hear about the next Hearthstone set over the next few months, but some details may have leaked early due to a voice actress' resume.
Lani Minella has worked on many video game titles throughout her career including Mass Effect 3, Last of Us, and of course, Hearthstone. Someone trawling through noticed a new addition titled "Hearthstone: Lost Secrets of Un'Goro" which many are presuming is the title of the next Hearthstone set.
It names a few generic cards she worked on including Golakka Crawler, Pteradactyl, Anklesaur, Hydra, and Brontosaurus. In the past, she's voiced cards such as Faceless Summoner, Twilight Geomancer, Ancient Shieldbearer, Darkshire Librarian, Cult Master, Arathi Weaponsmith, and Imp Master.
Here's what our sister site Wowhead has to say about the area:
We imagine Blizzard may very well draw from the current list of 100+ NPCs that exist inside the zone. The Golakka Crawler is likely from the Golakka Hot Springs, where players have to deal some wandering spirits.
They may also borrow from the new Un'Goro Madness Micro Holiday where elite dinosaurs with 230 million HP spawn and stomp players to death.