Under normal circumstances, higher life forms were energy life forms. For example, the Flaming Beast, which exists among the stars, was a pure fire energy life form. There was also the Devouring Bug, which lives in deep tunnels as well as other life forms such as the Radium Bird, which lives in quasars and absorb energy through radiation. If these animals were made out of flesh and blood, it would be impossible for them to survive in such extreme environments.
This was because physiques made out of flesh and blood were too fragile and had too many flaws. It was also the same reason why most life forms would become energy life forms when evolving into a higher form of being. This was not only limited to humans, the same could be said of other creatures.
