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. Ironically, Mona begins behaving like Alison after she resumes Alison's place as a Queen Bee. She taunts Lucas and calls him a hermaphrodite, Alison-style.

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" begins 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 dis-invite Hanna from her birthday party. She also dis-invites 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.

In "Touched by an 'A'-ngel," Mona accompanies Hanna in blowing off school to try on her bridesmaid dress for Isabel's wedding. Before meeting her, Mona had formed a negative opinion of Kate, based on what she considered a hideously ugly gown. However, when she meets Kate, she immediately takes a liking to her style. When Kate invites Mona and Hanna to lunch, Mona accepts, while Hanna declines, frustrating Hanna. She accompanies Hanna on a trip to a horse farm, due to Mona's pretending she went to equestrian camp in order to fit in with Kate and her friends. At the farm, they meet Kate's friends. Hanna displays her ignorance about certain cultural references that Kate and her friends make, so Mona cuts in, laughing off Hanna's remarks, trying to save her friend face. Later Mona and Hanna are walking through some random woods, their faces stained with dirt. The girls had managed to lose Kate's horses. Hanna gets Mona to admit that equestrian camp never happened. Hanna snaps at Mona, accusing her of befriending Kate for selfish reasons, and Mona counters that Hanna has been bad tempered ever since Caleb left. Hanna later apologizes.

After returning to the stable, Hanna expresses to Mona her feelings that Kate and her friends were nasty towards her and also considered Hanna clueless. Mona suggests that Hanna wasn't trying hard enough, making Hanna really rail against her future step family and Kate's friends, calling the latter bitches who can go to hell. It turns out that Kate and her friends outside the stable overheard the whole exchange after Mona 'accidentally' set her riding helmet on the loudspeaker switch. The girls rush out to undo the damage, but Kate walks away miffed, with her friends at her heels. Mona does seem sincerely apologetic about her mistake and the fallout Hanna has with Kate and her friends.

Later in "I Must Confess," Mona is seen during Dr. Sullivan's assembly on cyber-bullying and rolls her eyes at Hanna, mouthing the word "boring."

In the prequel episode, "The First Secret," Mona is insulted by Alison after trying unsuccessfully to sit with her and the other Pretty Little Liars in the school cafeteria. Rebuffed, Mona goes next to Lucas' table.

The familiar scene where Mona spots Aria and Alison eating their frozen yogurt as they walk is replayed. Mona calls out to join them, and Aria looks inclined to stop, but Alison propels Aria forward in attempt to lose Mona. It is now revealed that this event took place on the eve of Halloween 2008. Mona has turned around, rejected, chilled, and upset.

Later on in the school hallways, Lucas bumps into Alison, dumping his drink on her. Angry, Alison rejects Lucas' apologies, mercilessly calling him "Hermie" and publicly suggesting that he's really a hermaphrodite. When Alison walks away, Lucas growls that she will get what's coming to her, and Mona nods uncomfortably in silent agreement, having witnessed the whole exchange. How Mona ever took to calling Lucas by that same insult is a mystery.

At Noel's halloween bash, Mona is dressed as cat woman. Alison doesn't seem to recognize her (though that's probably a good thing) when Mona approaches Alison and with a warm hello. When Alison asks if she knows her, Mona mysteriously responds no, but Alison will.

When Jenna saunters away from her own exchange with Alison, Mona declares her the best Gaga, and the two introduce themselves, seeming to start a friendship.

Trivia

 * Janel Parrish originally auditioned for the role of Spencer Hastings. After being informed she was not going to receive the part, she re-auditioned for the role of Mona, and received the part.
 * 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 cookie that reads "There's No Place Like Homecoming." (Dorothy's words at the end of the film: There's No Place Like Home.") Also, in "Can You Hear Me Now?," "A" sends a flier towards the Pretty Little Liars that reads, "Ding Dong, the Bitch is Dead," a reprisal of the film's song "Ding Dong, the Witch is Dead."
 * In "Touched by an 'A'-ngel," we learn that Mona can speak French conversationally.
 * In the book series Mona is "A" for the first four books. However, it has been confirmed that the tv series is going to be different, and the producers noted that "A" is a different person.