What is the embryo with 8-16 blastomeres known as?

Morula.

Morula is a very early embryo stage and it consists of 16 cells. These 16 cells which are known as blastomeres define the Morula stage. It is a solid ball that consists of the zona pellucida. The Morula stage is a stage in the process of blastulation and occurs before the formation of the blastula. The Morula occurs after 3 - 4 days of fertilization of the egg by the sperm. Hence, it is one of the important steps in the process of embryo development and the later birth of a child. During this stage, most of the cells in the Morula are totipotent and have the capability to produce an entire living organism as it can differentiate into different types of cells with specialized functions and thus is one of the primary steps in embryo development.