https://www.gamespot.com/articles/hearthstone-details-witchwoods-monster-hunt-mode/1100-6458366/

Hearthstone's latest expansion, The Witchwood, was released last week. A little piece of it was held for after launch, though, and Blizzard is beginning to open up about it. The single-player portion of the expansion is coming next Thursday at 10 AM PT. The new Monster Hunt mode will be similar to Dungeon Run from Kobolds & Catacombs, with a few significant differences.

Rather than your regular Hearthstone classes, Monster Hunts will be undertaken as one of four characters with their own unique hero power. Tess Greymane is a Rogue-type with Scavenge, which lets you Discover a class spell that has been cast during the game. Darius Crowley has a cannon that fires at enemies positioned directly across from it, and if it kills them, it refreshes and can be used again. The other two are Houndmaster Shaw and Toki the Time-Tinker, but Blizzard didn't reveal their powers yet. Similarly, there are new treasure cards as well as some returning from Dungeon Run.