Vorus'arak's Carapace

According to multiple reports, this item (which is needed for the Tell Me A Tale achievement) will be received after completing an island expedition where you killed Vorus'arak. He spawns on Skittering Hollow when Nerubians are there, typically in the pit in the middle of the island.

This quest is turned in at Kilix the Unraveler at the entrance to Azjol-Nerub in Dragonblight.

Hopefully this helps!

This is kind of a sad story.
Vorus'arak escaped from some spider war and managed to avoid the whole Lich King debacle only to die at our hands while we greedily pursued Azerite while fighting a war someone else started...
Cool to see the Nerubians again but was really hoping for more of a "he was a jerk who deserved to die" kinda story.

Finally got it today, while doing Skittering Hollow in normal mode. For Vorus'arak to appear you need to have a Nerubian drawing on the Island Expedition table, but even then it can take you multiple runs for this rare to appears.

I had a macro "/target Vorus" and after 5 or 6 Skittering Hollow where it wasn't there, we found it in a little cave (coords 47 53). Both me and a friend tag him, and we both get the quest.

Also note that this rare spawns at the very beginning of the IE. It's not one of the extra rares that appears mid-expedition. So if you don't see it in the first 2 minutes, you can probably just quickly win the IE and queue for another one.