Mummification odor is:
Ref. Textbook of forensic medicine. Krishnan Vij. Page. 96 
 
Mummification
Mummification the shriveling up of a tissue

The Optimum Conditions for Mummification - dry & warm climate
Once the changes are complete, the body will remain in that condition indefinitely.
Also seen in newborn infants (sterile)
It’s odourless
No growth of micro organisms. Mummification is partial
25% of body weight is preserved.

Medico-legal Importance of Mummification

Identification
Time estimation
Cause of Death
Pungent
Putrid
Odorless
Rotten