@RoboRomb
A secies in space is implausible, but not impossible. The thing is, while some sort of cell-like organism can easily survive in space, and could evolve in space, a sentient organisim is different.
@reeper66
Yes, that is one way. Another is for it to be like an animal, but feed off of something else. Taking methane from planets, and taking energy (Less likely), or, it might not even be an organisim like we think of it! (A cloud of gasses kept stable via magnetic fields. The placment of the gases generates magnetic fields, keeping it stable, and electric pulses through the gas. Now, this entity absorbs energy like a plant, but uses it differently. Basicly, giant, gas based lichen)
@Rednascar11
a space based organisim should be capable of going though at least thin atmospheres, and probally more!
See: Leviathan
It’s a pretty fair idea
and, how did this get from air to space? Well, at least space is cooler! In more ways than one!
I think that a underwater civilisation hasn’t been given enough thought.
The tardigrade idea would work perfectly.