Ramiel's Protector

This unnamed demon worked for Crowley.

History
He and another demon were tasked with keeping an eye out for Prince of Hell Ramiel, as part of a deal Crowley made with Ramiel.

When Mary Winchester leads a team of four people to infiltrate Ramiel's house, Crowley sends these two demons to attack and kill the group. While the other demon fought Wally, this demon attacked Sam Winchester. Despite gaining the upper hand, Sam was still able to stab him with the demon-killing knife.

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.
 * Super Strength - This demon was strong enough to knock Sam over and beat on him.

Weaknesses

 * Higher-Tier demons - As a low-level demon, he was subservient to and weaker than higher level demons as shown by him working for Crowley.
 * Demon-killing knife - He was killed with this knife.

Appearances

 * Season 12
 * Stuck in the Middle (With You)