Answer:
Morula: a solid ball of cells resulting from division of a fertilized ovum, and from which a blastula is formed.
When is it formed: In humans, the blastocyst is formed approximately five days after fertilization. This stage is preceded by the morula. The morula is a solid ball of about 16 undifferentiated, spherical cells.
tbh i don't really know when it's formed, but i looked it up and that's what it gave me. i hope it helped :)