Alison DiLaurentis (Pretty Little Liars)
Alison DiLaurentis
 (Sasha Pieterse) is the secondary main antagonist on Pretty Little Liars.

Alison was the natural leader who loved to devise strategies to solve complex conundrums. She's skeptical and sometimes cynical, who demands perfection from herself and the people around her. Alison was originally the Queen Bee of Rosewood, due to her sociopathic behavior. She was a compulsive liar and black-hearted bully, ultimately before she changed her ways.

Although Alison seemed to have it all, she was easily threatened by people who intimidate her. Her jealousy and need for power often got the best of her and caused her to act cruel and selfish; likewise her fearless nature had helped her to get revenge on her enemies numerous times. Alison was vindictive and cunning, she often used other people as tools in her manipulations - she was the snake behind an angel's face.

Nobody told a lie better than Alison. She had a way of using people's secrets against them She had kept lots of information about her life from her friends, while managing to acquire all of their secrets. Alison often held private knowledge of her friends over them to stay in control. She spun a web of lies so tangled that her friends were left to deal with the resentful "A" when she was on the run.

Since Season 5B and onwards, Alison's personality has changed significantly. She has become a better person. She is now more reserved, and wants nothing more than to be happy. Though, if someone or something threatens her or her friends, she has no problem letting her "bitchy" side shine through. 

Though Alison has become less threatening, she is NOT a pushover. She has been through so much, yet she is still so strong.