The Mesopotamian mythology represents a variation of monsters and hybrids. Among them, the fantastic creatures in the composition of the animal and the man are very important; it is about the "man-animal". What attracts our interest; it is the composite creature, the "man-bull", because of its diverse aspect, as well as its symbolic characteristic. On the other hand, we notice one of the very practical figures and very renowned, "Master of animals", it is appreciated as much as all the Mesopotamian regions represented it in their arts. Problematic: what types of the "man-bull" had most importance in Mesopotamia? Which is the relationship enters the "man-bull" and "Master of animals"? What physical evolution arose during the transformation of the "man-bull" to "Master of animals"? Hypothesis: there is doubtless a narrow relation enters the "man-bull" and "Master of animals ", as regards the symbolizing character to be able to it and their appearances in vertical position. Mesopotamia represents a particular character of the real or fantastic animals, which spread towards the other parts of the country; it is about the representation of animals in vertical shape.