Meg Masters (Demon)

Background
Meg lived in Andover, Massachusetts until she was possessed by one of the demons. Much of her background is not known except that she left her family.

Season 1
Sam has left Dean and is traveling to find his father in California when he encounters Meg, who is also hitch-hiking. their first encounter is brief, as she soon gets a lift with "sleazy van guy". She later turns up at the bus station and she and Sam bond over feeling trapped by their families expectations. Meg tries to dissuade Sam when he leaves, concerned Dean is in trouble. At the end of the episode, Meg is again hitch-hiking. She gets the driver to pull over and then cuts his throat with a dagger, collecting his blood in a goblet. She swirls the blood with her finger, and after a Latin incantation, communicates with someone she calls "Father", which was actually the yellow-eyed demon. It is revealed that she was well aware of who Sam was.

The boys run into Meg in a bar in Chicago. Sam is immediately suspicious of this coincidence and follows her, finding she has a black altar set up in an abandoned warehouse, and is controlling the daevas. She again uses the goblet of blood to communicate with someone she reports to. The whole set-up is a ploy to lure John Winchester and the boys to Chicago, but she fails despite capturing Sam and Dean when her altar is destroyed and the daevas turn on her. She plummets from the building many stories down to the sidewalk. However at the end of the episode, she is seen alive and well, watching the Winchesters go their separate ways.

Meg murders John Winchester's friends Pastor Jim and Caleb, in order to force him to hand over the Colt. She gets John to come to a warehouse in Lincoln, Nebraska on the corner of Wabash and Lake. Here, he hands over a fake Colt, which is discovered when Meg's "brother" Tom shoots her with it and she doesn't die. She and Tom then capture John Winchester.

Meg calls Dean to reveal she is holding their father. Later she tracks them down at Bobby's place, but is captured under the devil's trap. Sam starts to exorcise her, while Dean interrogates her as to their dad's whereabouts. Bobby points out to them that she is actually a woman possessed by a demon, and that because of the injuries she sustained in Chicago, will die when the demon leaves her. The demon leaves, but the human, dying, Meg tells Sam and Dean where John is being held.

Season 2
The demon that had possessed Meg has been in hell - which it describes as "It's a prison, made of bone and flesh and blood and fear". It has escaped to possess Sam, planning to kill hunters and try to provoke Dean into killing Sam. It no longer gives a "rats ass" for the plans of the The Yellow-Eyed Demon. While possessed by the demon Sam's smokes menthol cigarettes and drinks hard liquor. While in Sam's body the demon kills a hunter, Steve Wandell, and using Jo for bait nearly kills Dean. It goes after Bobby, but is revealed when Bobby gives it beer laced with holy water. Bobby and Dean trap it beneath a devil's trap, but they find it difficult to exorcise because it has used a spell to bind itself to Sam's body. Bobby finally burns across the binding brand, and the demon is exorcised.

Season 4
Meg is briefly resurrected when the "Rising of the Witnesses" seal is broken by Lilith in "Are You There God? It's Me, Dean Winchester". She goes after Dean Winchester and tells him how much she suffered because of the demon. She also mentions her sister committed suicide after learning about Meg's death. However, she is eventually put to rest by Bobby Singer.

Season 5
Meg returns, this time possessing a different human.

She is first seen in episode 1 "Sympathy for the Devil" She locates Dean and Sam after his freeing of Lucifer, she intends to kill Dean to prevent him from killing her "Father" Lucifer.

She also appears in episode 10 "Abandon all Hope" and is in control of 8 or so Hellhounds, and sets them after the Group. She appears to idolize Lucifer, calling him father, and serving him loyally, when Castiel (Misha Collins) mentions the demon named Crowley, she calls him a traitor.

She abandons her regular human vessel in episode 12 to possess a teenage girl in order to find the location of Sam and Dean. She is exorcised by the end of the episode.

Season 1

 * "Scarecrow"
 * "Shadow"
 * "Salvation"
 * "Devil's Trap"

Season 2

 * "Born Under a Bad Sign"

Season 4

 * "Are You There God? It's Me, Dean Winchester" (as the ghost of the woman she possessed)

Season 5

 * "Sympathy for the Devil" (possessing a different body)
 * "Abandon All Hope..." (possessing a different body)

Trivia

 * Meg is from Andover, Massachusetts
 * Meg has a sister who killed herself after her death.
 * Her phone number is 312-555-0143
 * Meg was possessed around October 2005
 * In 2.14 Born Under a Bad Sign, the same demon that possessed Meg, possesses Sam. This demon is often referred to by fans as the Meg!Demon. When Sam is possessed he is referred to as evil!Sam.