Large Scarab Coffers are located in throughout the Temple of Ahn'Qiraj.
A 
[Greater Scarab Coffer Key] is needed to open one.
Contents
Large Scarab Coffers always contain at least one 
[Scarab Bag] and randomly one or more of the following:
[Idol of Night]
[Idol of the Sage]- [Idol of Strife]
- [Idol of Death]
- [Idol of the Sun]
- [Idol of War]
- [Idol of Life]
- [Idol of Rebirth]
Patches and hotfixes
Patch 1.9.0 (2006-01-03): Added