Many Egyptian gods had animal forms and characteristics, and some localities worshipped particular animals. They probably revered the animals' strength, beauty and usefulness to mankind, and also, because in some cases they feared them, they may have sought to placate them through deification. In some temples, there was a cult-animal (the god's manifestation) which was revered. At death, the cult-animals were mummified and buried; there were also vast cemeteries containing animals that pilgrims to sacred sites had purchased to honour the god.
Biographical Dictionary of Ancient Egypt by Rosalie and Antony E. David
Ancient Egypt. A Reference Guide. EdwART. 2011.