I was thinking that the muscles would be specialized for pulling the wings down and the hydrogen could help pull them back up, also forgot to mention that it’d be much less stable if they were in the middle. And in regards to the brain being not all the mass, I know, I was just using that to show that it wouldn’t need way too much hydrogen, and the creature doesn’t use blood, it uses water to spread sugar through its body, and oxygen comes through the lungs and fills its whole inside.
I don’t know, I guess i was just assuming something that was photosynthetic was a plantoid.
EDIT: It’s been a while since I got any feedback, does that mean that plant civs are possible?