Earlier this month, a voice actress's resume revealing a potential Hearthstone expansion was leaked teasing a possible expansion featuring Un’Goro
Recently, the next expansion to Hearthstone was confirmed to be Journey to Un'Goro. The expansion will bring 135 new cards with some new features. Quest cards are pretty self-explanatory, in that they contain quests which players try to complete before the opponent does.
The Adapt keyword, when shown on a Minion, gives an opportunity to buff said Minion with 10 available adaptations.
A new type of Minion called Elemental Minion is also coming, and some Minion types from older sets will be given the new title. New cards are to be revealed on 17 March, and the expansion itself will launch in April together with the Year of the Mammoth.