Captured Demon

This unnamed demons was captured by Ruby and Sam Winchester as a test subject.

Powers and Abilities
This demon appeared to be a regular low-level demon with the powers of one.
 * Demonic Possession - As a demon, he needed a vessel to walk the Earth.
 * Immortality - As a demon, he would never age or die unless killed.
 * Invulnerability - As a demon, he was invulnerable to normal methods of harm.

Weaknesses
As a regular low-level demon, he possessed all the weaknesses of one.
 * Devil's Trap - Like all demons, he could be bound by a devil's trap.
 * Special Children - While training his abilities, Sam was able to partially yank the demon from his vessel. However, due to Sam's lack of control resulted in him being unable to exorcise the demon properly.
 * Demon-Killing Knife - Like all low-level demons, he was vulnerable to the knife.

Appearances

 * Season 4
 * I Know What You Did Last Summer (flashback)