Malfurion is joining the Book of Heroes adventure later this month on June 22. Completing his story will reward you with a Druid pack and we should also be getting the option to purchase his new hero skin in the shop.

Quote From Blizzard

As the first druid, Malfurion has solemnly defended the natural world from threats, including his own brother, for thousands of years. Despite his steadfast protection, the perils of Azeroth have only increased with time, and the enemies of the wilds grow in both strength and cruelty. Malfurion’s harrowing tale will be told in Book of Heroes Malfurion, launching June 22nd. Defeating all 8 bosses in this linear adventure will reward 1 Druid pack, containing only Druid cards from Standard!