User blog comment:Sky-Dragoon-Twilight/What do you think the unseen Exceed races look like?/@comment-26574213-20150805184512

Demonia are like large monsters I think? There are ones that walk on two feet. (Volume 6)

Dwarves probably look identical to humans except possibly smaller. (Volume 7)

I don't think the Old Deus would have any certain form, they could probably shapeshift at wish. Or rather, the top 3 races in general might not have any definite shape.

From the author's tweets, it's likely that there's raks in the Elemental race, from little non-sentient elemetals to great elementals that can have humanoid shapes.