When we notice his face has human like, but too big to fit through the earth. So, he’s more of an alien.
He was a humanoid scientist before the ending of the last universe.
Galactus was a humanoid alien called Galan from the planet of Taa
What is it with you and making posts where you answer your own question?
To make a simple explanation where I get to know their history.
What do you think?