Is Cetus a dragon?

Could you elaborate on the classification of Cetus and whether it falls into the category of a dragon? Is there any specific criteria that determines if a creature is designated as a dragon? If Cetus is not a dragon, what are the key differences that distinguish it from a dragon? Perhaps there are distinguishing features in its appearance, habitat, or behavior that separate it from the traditional dragon archetype. Clarifying these points would greatly assist in understanding the nature and classification of Cetus.