Did the Egyptians only mummify certain people?

Anyone could be mummified, and mummification was desirable, since the Egyptians believed that the process allowed the soul to live on after death. However, it was expensive, so common people were rarely mummified. Pharaohs, government officials, and members of the nobility were often mummified, as were some animals (cats, birds, baboons, bulls, and other animals that held special religious significance in Ancient Egyptian society).