Carl's demon

This unnamed demon possessed Carl, the Tran neighborhood mailman under the orders of Crowley.

Season 8
At some unknown point in time Crowley had several other people affiliated with Linda Tran possessed by demons to keep a lookout for Kevin Tran who he wanted to recapture, this demon chose to possess Carl the mailman.

After Kevin reunited with Sam and Dean Winchester they went to Linda's house to see if she was safe. After staking out the house for some time Sam and Dean realized that Carl was a demon due to him filling the mailbox three times since the group arrived.

After taking out one demon the boys then attempt to take out the demon. This demon is walking along the street in front of the house when he hears a noise from near the house. His eyes turn black as he goes to investigate. He walks through the unlatched gate to the back yard and finds Dean standing there. Dean waves as Sam steps out from behind the gate and stabs this demon with the Demon-Killing Knife, killing him. The demon drops to the ground, dead.

Powers and Abilities
This demon was a regular low-level demon with the powers that come with one.
 * Demonic Possession - Like all demons, this one needs to possess someone to manifest on Earth.
 * Immortality - As a demon, this demon was immortal unless killed.

Weaknesses
He possessed weaknesses inherent in all demons
 * Higher Demons - This demon was subservient to the Crossroad Demon Crowley.
 * Demon-Killing Knife - He was killed by this knife.

Appearances

 * Season 8
 * What's Up, Tiger Mommy?