Have you ever been possessed by someone

Have we ever seen a demon manifest without possession?

The crash

Aside from yellow eyes that appear as smoke, in the last two episodes of season two while Sam and the other psychics are in this little abandoned village, there are a few demons that manifest without owning them. For example, the little girl who turned to smoke instantly when she was hit by the iron bar, which of course wouldn't happen if the girl had just been possessed. We have also seen many crossbreed demons appear and disappear in ways that seem impossible if they simply possess someone. As Bobby points out in a later season, demons are just "ghosts with an attitude" and therefore follow the same rules as other ghosts (thereby burning the bones that kill them), and since then we've seen many ghosts move visually and manifest physically As the series progresses, it stands to reason that demons can do the same thing.

KutuluMike

Teleporting crossroad demons was one thing that crossed my mind, but angels also appear and disappear at will and we know they all possess human bodies (their true form would blind anyone who looks at them). However, I had forgotten the demons in Azazel's survival camp.

Izkata

The acheri demon is a kind of ghost: "In Indian folklore, an acheri is the ghost of a young girl who visits from her mountain at night to bring disease to children." It is simply called "demon" although it is not a supernatural style demon similar to the rakshasa. Granted there is some Overlap, considering how supernatural style demons arise, so the Acheri demon could be in between at some point.

WakeDemons3

The answer to that question is now "yes". In the season 9 finale / season 10 opener, Dean manifests himself as a demon with no possession after Metatron "killed" him. The mark of Cain brings him back as a demon.

Conclusion:
It's Dean as a demon when nothing possessed him.

amflare

This can be a great answer as you work this out further. In what episode did that happen? Is there a section where the characters leave comments on it that you can paste the script for? etc.