Mona Vanderwaal

Biography
Mona Vanderwaal is a Dutch-American student at Rosewood High School. She is a former nerd that used to idolize Alison DiLaurentis in the shadows. She transformed herself to Rosewood's "It Girl/Queen Bee" along with one of Alison's former friends, Hanna Marin.

Mona, afraid of falling down to the bottom of the social ladder, scolds Hanna for her secret doings, telling her that if she does one thing to bring her down back to "dorkdom," she'll be going down alone. Deep down, Mona will never forget the way Alison treated her, but being popular, there was no time to be sentimental about things from the past.

Mona shoplifts to relieve herself of all the pain. She has never been caught due to the fact that she has become so good at it. She and Hanna became best friends when Alison's crowd gets disbanded. Mona figures that Hanna would not give up the chance to become popular. Their friendship stays strong until the ever so infamous "A" begns torturing the girls, forcing Hanna to become closer to them once more. The other Pretty Little Liars, besides Hanna, don't care much for Mona, and this is a minor source of conflict in certain episodes.

Season 1
In one of Aria's flashbacks, early in the series, Mona is shown with glasses and pigtails, trying to hang out with Alison and Aria. She asks them to wait up, but Alison tells Aria to ignore her, and cruelly, Aria obeys running away from dorky Mona. Mona is crushed and wraps her arms around herself to warm up.

In the episode "Keep Your Friends Close," Mona is throwing a birthday party for herself, which she calls "Camp Mona" and gives select invites to her friends, including Hanna and the rest of the liars, as they are her BFF's friends. The rest of the liars aren't interested, though Hanna tries to persuade them to come and that Mona has redeeming qualities, but they do not change their minds. This changes, though, when "A" tells the Liars that information will be revealed at Mona's birthday party.

Then, Mona hears a rumor (thanks to a text from "A") that Hanna became skinny thanks to liposuction. Mona breaks off their friendship due to anger, going as far as to disinvite Hanna from her birthday party. She also disinvites her because Hanna refused to ditch school with Mona, despite Hanna's mother giving Hanna plenty of cash to spend on Mona. So, ironically, Spencer, Aria, and Emily attend Camp Mona without Hanna. Camp Mona turns out to be an over-the-top bash, complete with massage deck, food tents, makeshift hair parlor, and matching T-shirts for all attendees. Her gift table is piled high with presents.

In the next episode, when Hanna is hospitalized due to her run in with "A" at the end of the party, Mona visits her in the hospital and apologized, realizing that she was mad at Hanna for a stupid reason. Hanna gladly accepts her apology and they become BFF's once again. While visiting Hanna, Mona told Hanna the reason she chose her to be her best friend. At a party, chubby Hanna vomited while on the trampoline. When she realized everyone was laughing at her she bowed, no longer affected by peoples remarks. Mona found that to be a life lesson. Mona believed that if Hanna could get over peoples teasing and ignore it, so could she.

Mona throws a surprise "Welcome Back!" party when she was released from the hospital. Mona and Hanna are still BFF's but not like before. Their friendship isn't as strong, due to the fact that Hanna's relationships with her former BFF's, are growing once again.

Mona is not seen in a few episodes until she appears in "The Badass Seed," gossiping with Hanna about her morning shower with Caleb. Mona is in the school play with the rest of the Liars; she witnesses Aria call Mr. Fitz "Ezra."

In "Monsters In The End," she destroys a letter from Caleb, expressing his love for Hanna, due to the feeling need to protect Hanna from being hurt again. Hanna does not find about this until later and thinks even more badly of Caleb as a result.

Season 2
In It's Alive, when Hanna finds out from Caleb that Mona never forwarded Caleb's goodbye letter to her, but instead lied, leading her on to believe Caleb was worse than he was, she is distressed and angry with Mona.

Noel Kahn returns to school in the same episode, and Mona begins dating him, to Hanna's surprise, but as Hanna is angry with her friend for lying to her, she doesn't question her about it, though she doesn't understand. Eventually, Hanna confronts Mona later in the episode, just before her date with Noel. When Hanna leaves, Noel detects something wrong, and Mona just sulks.

In the next episode, when the Pretty Little Liars' parents have placed a ban on them hanging out together, the girls sit at different lunch tables. Mona tries to invite Hanna to sit with her, but Hanna is still too sore at her to be her friend again, so all five girls sit at separate lunch tables, eating alone.

Hanna and Mona eventually rekindle their friendship; Mona calls it spiritual. They agree to keep their romantic lives (i.e. Caleb and Noel) out of discussion for the time being, while their friendship repairs, in order to avoid more arguments. However, Hanna does find out why Mona is dating Noel: "He has bad-boy cred now too." (On his suspension)

Later in "Never Letting Go", Mona takes over as the boss of the fashion show. Spencer expresses an intense dislike for Mona's attitude. Despite her bossiness and aggression she is able to have the show run smoothly until "A" sabotages the Cd's. In an open display of favoritism, Mona appoints Noel as fashion show DJ.

Trivia

 * In "Never Letting Go", Mona mocks Aria at the fashion show dress rehearsal while Aria is practicing her catwalk: "Are your legs always that short, Aria?" In the same episode, Spencer alludes to Mona being five feet tall. Mona's and Aria's wikia page both show that they share the same exact height: 5"2!
 * Mona along with Hanna have appeared in character in commercials for TRESemme hair products. Including TRESemme climate control and TRESemme Fresh start.
 * Mona is up on her Wizard of Oz references, as she tells Lucas in "The Perfect Storm" to ask the wizard to make him a man. "A" is up on her Wizard of Oz references too, custom designing a fortune that reads "There's No Place Like Homecoming." (Dorothy's words at the end of the film: There's No Place Like Home.")