|Powers and Abilities||Possession, fuel a person's anger.|
|Vulnerabilities||Varies; salting and burning the physical remains or object they are tethered to.|
|Appearance||Varies; the form of the deceased, which may have visible signs of trauma or decay.|
|Episode(s)||8.06 Southern Comfort|
A spectre is an avenging ghost. It, uh – it possesses you and finds out whatever betrayals you're feeling and forces you to act on them.
Spectres are a particular type of avenging ghost that possess a person. They will sense their grudges, and cause them to act against the person who wronged them. They can be distinguished from other vengeful spirits, and from ghosts in general, in that they leave behind green rather than black ectoplasm. Both Vance Collins, and the last spectre Bobby Singer encountered, according to his journal, rose after someone desecrated their graves.
Unlike typical possessions, spectres allow the possessed a semblance of control and awareness; they will fuel the rage a person has over someone, but the anger will not be indiscriminate, as shown when Dean does not shoot Garth when he comes between a possessed Dean and Sam. Spectres can also sense a person who has suppressed feelings of anger or betrayal and will seek them out as hosts.
A spectre thrives on a person's personal grudges, but is powerless when confronted by someone who holds none, such as an innocent kid, or Garth, who just lets "all that stuff go."