Hearthstone's Whispers of the Old Gods is bringing with it four legendary minions who are those famous eldritch abominations.
While we've encountered C'thun and Yogg-Saron in WoW, and N'Zoth is presumably going to face our wrath at some point later down the line, Y'Shaarj never got a chance. Slain by the Titans way back in the day, it was Y'Shaarj's death and the catastrophic damage to the planet that followed that convinced them to leave the other Old Gods alive, but hopefully contained. Y'Shaarj was arguably the main driving force behind Mists of Pandaria, as he released the Sha upon the land in his death throes.
So what did this guy look like? The beast with seven heads, most powerful of the Old Gods?
See beyond the cut!
Yep, there's the nasty guy. We did see a brief glimpse of some representation of Y'Shaarj in the shrine below Klaaxi'vess, and it looks like the two shell-like shapes on the side of its head are there. Notably, Y'Shaarj has a similar facial shape with the Sha, especially with the various eyes (except the central one in its forehead.) It's likely there will be a larger picture that shows more of Y'Shaar's body, but right now it looks a lot more spindly and thin than the other Old Gods.
To speculate on mechanics, I'd suspect that there might be a large body (maybe even 10/10) and then a death rattle effect that summons seven Sha, which might each have complementary abilities or maybe just big bodies.
Anyway, it's pretty cool to finally get a face to put to the name.