Black Dogs

A black dog is a supernatural creature.

Characteristics
When Sam and Dean were solving a case involving a wendigo, they thought of a black dog as the creature responsible. Additionally, they also considered black dogs to be the suspects when dealing with hell hounds for the firs time. From this, it could be gathered that they have similarities with hell hounds and wendigos. However, Dean said that lore on the black dogs are pretty vague. While some consider them to be animal spirits while others consider them to be death omens. To date, Sam and Dean have never encountered an actual black dog.

Pad of Definitions
The Pad of Definitions from the official website of the show provides two entries on black dogs.

Appearances

 * Season 1
 * Wendigo
 * Season 2
 * Crossroad Blues