Vivian Darkbloom

Vivian Darkbloom is the alter ego of Alison DiLaurentis. After Caleb begins hacking "A's" phone, the girl's discover that Alison had created an alter ego, after she too was being victimized by "A." The name "Vivian" comes from Latin, and it means "Alive." The full name is also an anagram of "Vladimir Nabokov" who wrote the novel "Lolita". Very few people know Vivian's true identity, some of them are Duncan Albert, the four liars, and possibly Mona Vanderwaal.

Appearences
Vivian is first introduced in "A Kiss Before Lying", when Caleb hacked the video to see her photo license. Hanna then remembers that she once saw Alison with dark hair in a hair salon. She recognized her voice and was suprised to see her with a wig, but Alison told her that it´s just her hobby - pretending to be someone else.

In "UnmAsked", Aria and Spencer discovered that the day Alison disappeared, Vivian stayed in the Lost Woods Resort. Mona later remember that she saw Alison/Vivian in a shop in Brookhaven spying on someone, asked her who she was spying on, to which Alison told her to play along to the idea that they did not know each other. With Mona's unwavering desire to become another "Queen Bee", she kept Ali's secret, to which she received a card with phone number in return. At the end of the episode a person in a red coat visits Mona in the hospital, to which she says "I did everything you asked me to", implying this person is the leader of The "A" Team. It is unknown if this person is Vivian.

In "It Happened That Night", when Hanna visits Mona at Radley, Mona is seen smiling at empty chair (assumed to be empty for Hanna). This is where Mona sees Vivian reading Lolita.

Many fans speculate that Red Coat and Vivian Darkbloom may be the same person due to their multiple similarities, the most prominent being the fact that both wear a signature red trench coat. However, this has not yet been addressed on the show.