|Right now I'm feeling happy, sad, confused, enlightened, worried, hopeful and hungry all at the same time. Is this normal?|
|—Frankie Stein in her 'Basic' diary|
In Latin American Spanish, when the series was dubbed in Colombia, she was voiced by Nathalia Gutierrez in volume 1 and 2, now, when the series began to be dubbed in Mexico, she is voiced by Karla Falcón since volume 3.
Having been born as a 15-year old only recently, Frankie's history is almost non-existing. She was created by the Frankenstein Monster and his bride at a lab in their current home, when the two decided it was time to raise a child. Made out of spare body parts, and was created with the physical stature of a teenager. Almost admittedly after her "birth", she was enrolled to study at Monster High, where she has been studying ever since, learning about life and gaining the experience she lacks. That is mostly why her age is more considered 15 days.
Frankie is a young girl, the youngest at Monster High at least, and this lack of experience of common day-by-day things makes her also the most naive. She started out from scratch, with a world of amazing things to discover, a world she is willing to explore and grow withm in fact, she is one to try everything that comes her way, from school activities to gastronomy. Because of this she has little to no concepts or social stigmas implemented on her, making her most prominent streak her acceptance of the strange and others. To her, everyone is worthy of a voice, and she herself is an activist that will stand up to any form of descrimination or bullying. However, this absence of filters isn't always a good thing in her case as she fails to recognize the good from the bad most of the times, so she's prone of being taken advantage of.
With everything being new to her, she is very impressionable, and at times insecure about herself and if she's taking the right turns, which in the past lead her to place her trust on teen magazines, although their advice often cause awkward moments for her, so she has learnt to be herself and has been rapidly gaining ground, though, mostly with the support of the close group of friends she created around herself., which she is. Not afraid to act aside from what's expected, she's quircky and silly, and the fact that she is made of stiched together parts makes her incredibly clumsy too, always making a racket where ever she goes, but she has grown used to it.
Despite setbacks, she remains upbeat, hopeful and determined, always positive and considerate towards her friends, and is definetly charismatic and outgoing and open to others. Somethimes a bit of a chatterbox, she finds in every stranger a friend and a story she can't wait to learn, so she isn't hesitant to make new friends, which sometimes can lead to dissapointment when the world isn't willing to put up with her. She can sometimes get a little carried away with her feelings, mostly speaking without thinking and making acusations that aren't always true.
Befitting her heritage, Frankie has an interest in broad range of scientific subjects and she favors the practical side over the theoretical one, though she is quite fond of the sciences. This interest extends to sewing and cooking, both skills she excels at and has utilized to create other simulacrums.
Despite being only a few days old, Frankie's physical age is that of a fully-grown girl in her late teens. Also, despite been a monster made up of parts from different people, she has been created with a well-balanced, attractive body, unlike her father.
She has long white hair with black streaks, similar to her mother's hair, which may be inspired by the Bride of Frankenstein (see Classic Monster). She has light, mint green skin, and has a condition known as heterochromia which gives her odd-coloured eyes - one green, one blue (though likely from being assembled from multiple bodies, rather than genetics). Frankie has visible stitches all over her body, most obviously near the joints of her limbs, around her neck, and across her right cheek. She also has two bolts fixed into her neck, which allow her to absorb electricity to use as energy to keep her body working. Her neck bolts flash like a light bulb when she has an idea.
There are several plot-holes concerning Frankie's age in the series. If the webisodes follow the same timeline as the "New Ghoul @ School" special, she would have started school when she was 8 days old or younger. In "Party Planners", she turns 16 days old. For her to be consistently 16 days old, most of what happens in the webisodes would have had to have happened in the same day, although this can't be, as in "Frightday the 13th" she stayed overnight, which means she is a day older than what she is now. It is unknown how old Frankie is today but, her age is either 15 days old or 16 days old according to a few websites.
Over the course of the first book series Frankie's over a year old. Her SDCCI 2010 diary describes her first day alive, while the regular diaries start on the day she has just turned 16 days.
In the cartoon series, due to having pass yearly events, it is implied that she is over a year old by now. Meanwhile, on the back of Frankie's Picture Day box, her age is listed as "How many days has it been now?".
Without knowing it, Frankie is an icredibly powerfull monster, at young age. Though most of her powers are to do with electricity, from her lab heritage, she has a wide range of other abilities, most of them still fresh.
- Electrokinesis: Frankie can create and control electricity, either accidently or on purpose. Through her bolts, when she gets emotive, or through her body, mostly through her hands, Frankie can charge anything or shock anyone. She herself can be charged too, either by the Recharge Chamber from "Freaky Fusion" or simply by random flashes of electricity and lightning bolts.
- Magnetism: In "Bad Scare Day", it is shown that, when her two bolts are switched from one side to the other, reversing her polarity, Frankie can attract objects with magnetic proportions.
- Pyrokinesis: Frankie can create fire at times too, mostly due to her electrokinesis. She can do this by beaming electricity at flammable materials or by simply rubbing her hands.
- Chronokinesis: In "Boo Year's Eve", Frankie was able to stop time accidently, but then rewind certain people's actions, confirming then Frankie's ability to control time. Why she would have such power is unknown.
- Body Separation: Frankie can detach certain parts of her body and control them at distance, which she frequently does with her hand to reach tight places.
- Sewing: Due to being a monster made of various detached body parts only connected by stiches and strings, Frankie has developed a skill on sewing and tailoring, which is not only one of her favourite hobbies, but it comes in handy in times when her body is dismantled too.
- Life Creation: Like her father and grandfather, Frankie has been shown to creating life herself, such as Hoodude and the gingerbread boy.
- Cheerleading: Frankie's a talented cheerleader, part of the sublime Monster High Fearsquad, which brings her will to help others and her joy together to create the perfect activity for her.
While Frankie hasn't yet been in any relationships she has appeared to be interested in Andy from the Skull Shores movie, Neighthan Rott from the Freaky Fusion movie, Jackson Jekyll and, Holt Hyde. She also created Hoodude Voodoo to be her boyfriend
Frankie lives with both of her parents, named Viveka and Viktor Stein in the first book series, in "a house that looks like a cross between a Swiss chalet and a research lab" in the monster side of New Salem in the United States of America. Her parents moved there from, presumably, Germany many years before her creation. Both her parents are multi-disciplinary scientists and college professors, though her mother is not as obsessed over science as her father. Because the Steins waited for over a century before they considered themselves capable of giving a child a steady home, despite their strong wish for one, they dote on Frankie and do everything they can to keep her happy and safe.
Taking after her parents in the science department but not so much the responsibility department, Frankie has already created two other simulacrums herself: Hoodude Voodoo and gingerbread boy. As the former's surname suggests, they aren't considered part of the Stein Family, but the Steins have taken responsibility for them. At least in regards to Hoodude, it has been arranged that he gets to live at Kindergrubber's and it seems the Steins keep paying for his education and other needs.
Frankie also has one Uncle Egor, presumably the man who assisted her grandfather in creating her parents. Contact with him is good and he's the kind of man anyone can rely on.
Frankie is a friendly girl, outgoing and overall nice to everyone, so she has adquired quite a big list of friends. However, she truly prefers to hang out with her closest friends, mostly the rest of the Fear Squad, but also others outside of it.
Her first friend at Monster High was Draculaura. The two met during a lesson where none where paying attention and after a week of loneliness, Draculaura, with her friendly nature, was the first one to actually notice and talk to Frankie. The two are really similar in interests and personality so instantly liked each other. Both have proven that their friendship is more important to them than almost everything else, to the point where Frankie sacrificed her well being and life to save Draculaura (and Robecca) . The two take interest in fashion and rarely are seen having an argument, and Frankie considers her one of her bestest friends.
Clawdeen Wolf was introduced to her through Draculaura, and immidietly liked each other, in Clawdeen's case, mostly based on fashion sense. While not as accepting of Frankie's antics as Draculaura, Clawdeen is completely loyal to her friend and trusts her with her heart, and Frankie has in Clawdeen a best friend. The two give advice to each other and Frankie usually brings out a better Clawdeen, who's more driven by friendship then other goals, such as rivalries.
Despite Draculaura and Clawdeen being Frankie's ultimate best friends, in the end of the day Frankie ends up having a bigger history and stronger relationship with a different group of people.
Within these people lies Lagoona Blue, the friend that is always there for her in her hardest moments. In fact, the two met when Frankie needed someone to share insecurities and to vent to, and Lagoona always has wise advice to give her. The two are probably the most determined of the main six, so they are usually the ones driving the group foreward. But unlike Frankie's friendship with Clawdeen and Draculaura, Lagoona's friendship involves lectures, especially when Frankie isn't true to herself. The two respect each other deeply and understand each other's motives and personality.
Abbey Bominable is a great friend of Frankie, however, the two didn't start all that well. When the two were framed into punishment by Toralei Stripe, who lead the staff to believe the two were involved in a snow fight with each other on purpose, the two were submitted to a relationship fixing treatment and were obligated to walk around armcuffed to each other for an entire school day. So they did, and with it found that their personalities couldn't be more clashing. Frankie's outgoing personality contrasted with Abbey's coldness and reclusiveness, and Frankie saw in Abbey someone rude and unfriendly, despite it all being a difference in ways. When the two sort their problems a great relationship bloomed. The two are really close, and Abbey loves humouring Frankie, which makes them really close friends. Abbey is almost like a younger sister to Frankie, which to the young moster is something new, as she is used to being the one being taught how to act, yet finds herself teaching Abbey the ways of her country's lifestlye, and Abbey has always something to give back, by offering a kind hand and straight-foreward reactions.
Frankie's pet is a dog hybrid named Watzit which her father constructed from the parts of other animals.
In the Monster High books and TV specials, Frankie has five pet lab rats whom she calls the Glitterati; their names are Gwen, Gaga, Green Day, Girlicious and Ghost Face. They also appeared in "New Ghoul @ School" and "Fright On!".
In "New Ghoul @ School", Frankie had a crush on Deuce Gorgon. This caused issues when she lied and told Deuce's real girlfriend, Cleo, that she was dating him. Cleo became very upset, thinking that Deuce had cheated on her, but the issue was later resolved when Frankie came forward with the truth and surprised Cleo with a Justin Biter concert.
In "HooDoo You Like?" Frankie was concerned about being left out of the group for not having a boyfriend, and decided to make one for herself, creating Hoodude Voodoo. The ghouls explained that they would always be friends with her regardless of whether or not she had a boyfriend, and Frankie admitted that she didn't think that she was ready for boys just yet.
In the webisode "Miss Infearmation" Frankie develops a crush on Jackson Jekyll after saving him from being bullied by Manny Taur, and invites Jackson to come to Cleo's tomb party with her. She is upset when he doesn't show up in "Hyde and Shriek", because he had turned into Holt Hyde before entering the party.
She soon forms a crush on Holt, blushing at the nicknames that he gives her ("Frankie 'Fine' Stein", "High-Powered Hottie") and dances with him on the DJ deck in "Hyde and Shriek". This forms a love triangle between her, Jackson and Holt. After introducing the two to each other via video recording in "Dueling Personality", she realized she couldn't choose and "hit the pause button" on their relationships.
In the Monster High book series she has a crush on Brett Redding (a monster mad normie) with a very protective girlfriend, Bekka Madden. At the september semi he mistakes Frankie for Bekka and kisses her; causing her head to be ripped off. She briefly dated Billy Phaidin, after his friend Candace Carver gave him a makeover so he wouldn't be invisible and could woo Frankie. Frankie and Billy went to a Lady Gaga concert together, but after kissing and needing to rush home due to Billy's makeup melting and wanting to make it in time for Clawdeen's party, the two realize that neither one felt "sparks". Frankie then gets back together with Brett, because her feelings for him are stronger. Brett chose Frankie over Bekka.
- October 23, 2007: Mattel requests the trademark for Frankie Stein.
- May 05, 2010: The Monster High website goes live, featuring Frankie Stein's profile.
- May 05, 2010: Frankie Stein's profile art is revealed.
- May 05, 2010: Frankie Stein makes her animated debut in the Higher Deaducation commercial.
- May 05, 2010: Frankie Stein makes her 2D cartoon debut in "Jaundice Brothers".
- Early July, 2010: Frankie Stein's debut doll is released as part of the 'Basic' series.
- Early July, 2010: Frankie Stein makes her diary debut in her 'Basic' diary.
- Early July, 2010: Frankie Stein's debut plushie is released as part of the Friends series.
- September 01, 2010: Frankie Stein makes her Monster High book debut in Monster High.
- February 12, 2012: Frankie Stein makes her 3D cartoon debut in "Why Do Ghouls Fall in Love?".
- September 05, 2012: Frankie Stein makes her Ghoulfriends book debut in Ghoulfriends Forever.
- October 22, 2014: Frankie Stein makes her anime debut in "Monster High Life Is Amazing!".
- Mattel's director for global brand marketing, PJ Lewis, stated that "Frankie’s head mold is a bit more square than the rest, as Frankenstein is known for having a square shape to his head."