- Main article: M'uru (tactics)
|Race||Void god (Demon)|
|Location||Shrine of the Eclipse, Sunwell Plateau|
- This appears to be the "void" that the naaru transform into upon death. Although the other darkened naaru (K'ure and D'ore) have not become void beings, this might be the result of M'uru being drained by the Blood Knights.
- Entropius also appears as a "memory" summoned Argent Confessor Paletress in the Trial of the Champion.
- The name "entropius" is likely a derivation of "entropy", the amount of energy unavailable to perform work on a system, commonly construed to mean the level of "disorder" or "chaos" in a system. Entropy is also defined as the state in which all objects are moving toward a higher level of disorder. Jeremy Feasal states Void is nothing, absolute zero, and is not entropic.
- Patch 2.4.0 (2008-03-25): Added.