Meg Masters

Meg Masters is a demon with many names but is known by everyone as Meg after the girl she once possessed, and a recurring antagonist who appeared in Supernatural. The daughter of the demon Azazel, Meg served as his minion in season 1 and later as Lucifer's as well. Meg was the secondary antagonist of season 1 and 5, a minor antagonist in season 2 and an anti-heroine for the rest of her appearances.

She was portrayed by Nicki Aycox in the season 1 and Rachel Miner in the season 5 and 8.

History
Meg was the daughter of the demon Azazel and served as his minion. She followed Sam and Dean on their journey to find him and killed many of their hunter friends along the way. After they realized she was a demon, they exorcised her out of the young blonde whom she was possessing. But Meg returned in season with a new body: Sam Winchester. However, they once again found a way to defeat Meg, once again.

Meg returned two seasons later with a brand new body of a brunette girl, now serving as Lucifer's henchmen.

Following Lucifer's re-imprisonment in his cage in "Swan Song", Meg sought vengeance on Crowley for having helped trap Lucifer and taking his place as King of Hell; to this end, she made an uneasy alliance with Sam and Dean, needing more allies as her fellow loyalists were hunted down by Crowley's forces.

Meg was captured by Crowley at the end of "Survival of the Fittest" and was tortured by him for a year, but refrained from giving him the information he wanted from her, instead passing it on to the Winchesters and Castiel when they came to her rescue in "Goodbye Stranger". She fended Crowley off long enough for the boys to retrieve the angel tablet and escape before he killed her.

When Crowley himself arrived, Meg held him off and sent Sam into the crypt to get Dean and Castiel who she revealed she was in love with by calling him "my unicorn," a phrase she had used to refer to Sam's girlfriend. She remained loyal to the Winchesters when Crowley tried to convince her to turn on them; even though they planned to seal all demons in Hell forever (including her), she would help them simply because they planned to kill Crowley. They then fought but Crowley quickly overpowered and beat her down, taunting her that he could torture her for eternity.

After Crowley noticed Sam and Dean escape to the Impala, Meg deduced that Castiel's absence meant that he had already escaped with the tablet, which she taunted Crowley about before injuring him in the shoulder with an angel blade. In a fit of rage, Crowley stabbed her to death with an angel blade of his own.