Nythendra - Emerald Nightmare - Legion Alpha
It appears Nythendra is the first boss in the Emerald Nightmare but potentially you may have various different routes you can take
from the very start of the instance. Nythendra is a corrupt member of the Green Dragonflight.
The Emerald Nightmare is the first raid to be released in World of Warcraft: Legion and is scheduled to have 7 bosses.