Daughter of Frankenstein's Monster and his bride, or possibly mad scientists. Or maybe even both. In all continuities, she is stated to only be 15 days old at the start and attends high school as the "new girl". Plucky, fun-loving and klutzy, she is more often than not the main character.
By the second diary and season of webisodes, she seems to be aging regularly though is still measuring it by days.
Could be explained that she isn't actually 15 days old, she just says she is because it's easier than continually changing for every day she gets older.
The franchise recently gave up on the exact age, just stating it as "How many days has it been now?".
The rather disobedient daughter of Dracula. At 1599 years old, she's very eager to date and acts like a typical boy crazy teenager. Notable as being one of the only, if not the first, true vegan vampire, as she faints at the sight of blood and survives mostly on supplements and fruit, as well as running her own newsletter on the topic: V.A.M.P. - Vampires Advocating Meatless Protein. It's heavily implied that she was not always this way though. Her freaky flaw is fainting at the sight of blood.
The Atoner: Her diary actually implies that she is one. When her dad tells her that he wishes she'd return to "proper" vampire ways, she writes that she is resolved to never go back to how she was before.
Hidden Depths: Draculaura's most recent diary provides some tantalizing hints at quite the Dark and Troubled Past- her father, rather than the Dracula we know, is an even older master vampire (Bram Stoker's villain was a less powerful upstart who used her father's name to impress and terrorize locals til he fell prey to Laser-Guided Karma), who took in Draculaura (perhaps just Laura then) and her mother "when no one else would" over a thousand years ago.
Older Than They Look: She's 1599 years old at the beginning of the series. A big show was made of her turning 1600 as it was used for both a doll collection/line (Draculaura's Sweet 1600) and it was the main event of the third animated special.
Daughter of The Wolf Man. Known for being the most fashion centered amongst the girls, she favors gold. A little cocky but well meaning, she is very loyal and always willing to help out. Her freaky flaw is her fast-growing hair, which covers her body as well as her head.
The Rival: Also with Cleo (though she is gradually softening towards her).
Our Werewolves Are Different: While Clawdeen's features are consistently wolflike, she usually keeps her animalistic side under control... except during the full moon (when she becomes more daring and energetic than usual).
"Fur Will Fly" hinted the full moon was the trump card she used to beat Heath Burns (he didn't know that day was a full moon, and it gave her super-speed, beating him even with his head start).
Rapunzel Hair: Her hair is constantly growing—and not just the hair on her head, leading her to have to pluck and wax continuously (she has to do so three times a day, as noted by her "Dawn of the Dance" itinerary). However, it also allows her to be more experimental with her hairstyles.
Southies: She and her sister, but not her brother speak with a faint Bahston accent.
Unusual Ears: Clawdeen has wolf ears instead of regular ears.
You Gotta Have Blue Hair: Her Dawn of the Dance doll has a short acid green bob with brown in the back, while her Gloom Beach doll has purple hair to frame her face.
Her Dead Tired doll also has a purple underlayer while both of her school themed dolls have her normal brown colored hair.
It's explained in-universe that the one benefit of Clawdeen's constantly growing hair is that it allows her to be very experimental with her hair, and this is born out by the fact that of all the dolls she has gone through the most hair color changes so far.
Daughter of the Sea Monster. The most well-rounded and level-headed character, Lagoona spends most of her time in the water (either in the ocean or the school's swimming pool) and is the gang's resident surfer girl. She has no specific best friends, and hangs out with all of the characters and gets along with them. She is also captain of the school swim team.
Informed Ability: Lagoona is described as being the tomboy of the group, however she is usually just as girly as the rest of her friends.
Missing Mom: Lagoona is the daughter of Sea Monster, strongly implied to be the Gill-Man. Her mother was later revealed to be an ocean nymph with whom Lagoona has just as good as a relation as with her father. Only, ocean nymphs can't go far from their home, so while in the USA, only her dad can visit her.
Multicolored Hair: Lagoona has aqua blue streaks in her otherwise blonde hair due to the chlorine in the school's swimming pool.
Daughter of the Mummy. Resident Alpha Bitch and head of the Fearleading squad, she's known mostly for her wealth and icy personality at school. In truth, she's quite sensitive and down to earth, but has been groomed to think of herself as better than everyone else. This is starting to change though, thanks mostly to her best friend Ghoulia Yelps and current boyfriend Deuce Gorgon.
Heel-Face Turn: Cleo started out as a bit of a snob/bully, but has progressed into a supportive friend, especially in the Breather Episode about Ghoulia and Dead Fast.
Hidden Depths: Has been making notable steps towards treating others better, best reflected in the second season of webisodes and her second diary.
As of Season 3, she treats all of her female friends as she does Ghoulia - caring and compassionate but still dominant.
Hidden Heart of Gold: Her growth in becoming a nicer person comes to a head when she sends all ten-thousand of her royal servants to the comic auction that Ghoulia couldn't attend in order to win said comic for her. But, of course, the comic is slipped to Ghoulia discreetly, and Cleo tells the other ghouls not to let this info get around and ruin her rep.
Jerk with a Heart of Gold: Cleo can be quite stuck-up and mean to the ghouls, but is also happy to help them when there is a problem. She "secretly" thanks Ghoulia for all her help by getting her the rare Dead Fast comic.
Son of Medusa. The resident casketball captain, he's well known and well loved at school. His freaky flaw is his powers to turn people/monsters to stone, though the effect wears off after 24 hours.
Blessed with Suck: His stone gaze. Nowadays, he is able to control it so it wears off after 24 hours. When he was a kid, he accidentally stoned his first pet, Smokey. It's supposed to wear off on the anniversary, but Deuce doesn't know which one. Awww.
Cool Shades: He wears them at all times so he doesn't accidentally turn anyone into stone.
Fantastic Racism: In her diary, she implies that that zombies are not well liked for being hard to understand and their sluggish behavior. Ghoulia even buys a "Zombies are Monsters too" shirt to make a statement, but can't bear to wear it openly.
"Freaky Friday" Flip: "Freaky Fridate" has this happen with Cleo when Cleo accidentally touches one of Daddy's idols that Ghoulia's holding.
Frozen Face: Though she can occasionally force a rather pained-looking Un-Smile, a groan, or even, in the case of the webisode "Mad Science Fair", a truly epic Slasher Smile that only manages to dodge being terrifying by happening as she finally gets back at Cleo for using her.
Gadgeteer Genius: Not only is she the smartest ghoul in the school, but she once invented a two story tall trash-to-fuel recycling machine as a Mad Science Fair project. Season 2 has her use her computer and hacking abilities quite a bit.
One of Us: In-universe; the 2011 Monster High San Diego Comic Convention doll is Ghoulia dressed in a female version of the costume worn by her favorite superhero, Dead Fast, that she just happens to be wearing to Necro Con. She's also in the school's comic book club.
Our Zombies Are Different: Ghoulia can't speak anything other than zombie, but she happens to be the smartest student in school and prefers fast food over brains. Sometimes she might only do one major action but it makes or saves the day in each episode.
Phrase Catcher: "Ghoulia's right!" Pretty much every one of the main characters has said this at least once.
Spotlight-Stealing Squad: From her first appearance on she became a hugely popular character and has been in a majority of the doll lines. At this point, she is either tied for the most doll versions with Frankie or even has a few more, thanks to playset and store exclusive dolls.
Talking To Herself: Audu Paden also does the voice for Slo Mo and Manny Taur, both of whom Ghoulia has spoken to.
Student with an unknown alter-ego. The 4th generation grandson of Henry Jekyll/Edward Hyde. The newest transplant to Monster High...or shall we say transplants. Jackson Jekyll exists during the daytime and Holt at night, though neither, or Holt at least, seem to know about the other. Jackson is said to be nerdy while Holt is the school resident DJ. Holt is known as DJ Hyde in the Monster High books.
Early-Bird Cameo: Jackson is first mentioned in Deuce's diary and as his best friend in the official bio. He is mentioned again in Draculaura's and Clawdeen's.
Fantastic Racism: Jackson's first appearance in the webisodes shows us how "normies" are viewed by many monsters. Even Heath, his cousin, is a little embarrassed to admit they're related at first. Deuce, however, quickly accepts Jackson.
Hollywood Nerd: Jackson, especially to Holt, who complains about waking up in "nerdy" clothing.
I Just Want to Be Normal/Special: Holt experiences the former, due to his sometimes violent temper accompanied by uncontrollable flames, and Jackson feels the latter, due to being the only "normie" in an all-monster school.
Jekyll & Hyde: Well, duh. Neither one knows of the other until much later, though. Whenever one side is "awake", the other has a blackout, but continuities varied on the trigger for a long time. Originally, in the diaries, Jackson was awake during the day, but became Holt at night; in the books, Holt came out when the temperature got high, then turned back into Jackson when he had time to cool off; and finally, in the webisodes, Jackson turned into Holt if he heard loud music with a beat. This was finally addressed in Jackson's journal, explaining that "the volatile nature of [his] elemental side + [his] Hyde heritage + being a teenager = constant change."
Ship Sinking: First with Draculaura in the diaries, and then with Frankie in the webisodes. Yes, having two constantly altering personas makes dating very, very difficult. The second was subverted, though; Frankie took a break from them so they could focus on getting along and not constantly lashing out at each other, and now that they're on good terms with one another, Mattel is teasing at them getting back together with Frankie — particularly with her I <3 Fashion doll and their clothing styles starting to influence each other. The Frankie/Jackson Picnic Casket two-pack should bring resolution to this story when it comes out, much like School's Out Draculaura/Clawd did for their storyline in season two.
Ship Tease: Jackson with Draculaura at first, but it didn't last. Both of them with Frankie later on — twice over.
The Reveal: During 'Here Comes Treble', when Jackson is exposed to loud music, he makes a mad dash out of sight from public view. Unfortunately, he doesn't make it in time and changes mid running up the staircase where everyone sees him.
Asian Speekee Engrish: Subverted; people worried she'd end up like this when her diary was released because she's from the Himalayas and speaks broken English, but possibly to avoid Unfortunate Implications, the animated series gave her an accent reminiscent of the Heavy instead.
Ice Queen: Naturally enough, yet subverted; she just unintentionally gives this impression with her words often being short, sharp, and hurtfully direct. She explains in her profile that this is because talking is "an oxygen waste" in the freezing climate of her native home, causing a lot of them to conserve oxygen and words by being more direct.
Daughter of the Ghosts. The mysterious school gossip who anonymously blogs about all the behind-the-screams news at Monster High. Despite her intrusive nature, Spectra claims she's as "light and full of sweetness" as Angel Food Cake.
The Atoner: Implied with the ball-and-chain motif (see Shout Out). While it isn't clear what her "crimes" may have been, Spectra says in her profile that she "find[s] that it's unhealthy to focus on what one does wrong especially when contrasted with all the good one does in the unlife."
Hidden Depths: Heavily implied in her final journal entry, though still left ambiguous.
Invisibility: Well, she is a ghost. It comes in handy when you're the school's resident gossip.
Larynx Dissonance: Her soft, childlike voice highly contrasts with her angular features.
Malicious Slander: Subverted. Spectra never intended for her gossip column to harm anyone; she was just fascinated by the lives of the other ghouls and wanted to share their exploits with others, but was too shy to ask them for permission.
Same Character, But Different: Her doll persona/diary narrative is a stark contrast to her webisode identity - Diary Spectra is malicious, rude and a compulsive liar while her webisode identity is actually as soft spoken and sweet as her profile claims.
Shout-Out: Her ball-and-chain motif is similar to the chains that Jacob Marley's ghost wore as a representation of his earthly sins.
Heath Burns has the ability to control fire. He was at first an extra in the webisode "Substitute Creature" and shortly introduced as Draculaura's short-lived crush. Heath is a show-off and gets on the girls' nerves by being self-centered and insensitive. He's friends with most of the boys, but even they admit he can be annoying. In "Fear Pressure", we learn he is Jackson's cousin. Heath has appeared in the Monster High novels: He was at first introduced as a normie, but in the second book he was revealed as a RAD by sneezing flame. His book counterpart is more mellow and not as conceited. He's also had a doll.
Shameless Flirt In Love: Has this with Abbey. The other ghouls thought he was just messing around when trying to ask her to the dance, but he was actually serious about it.
Out of Focus: Not in the webisodes, but in the doll line. Despite the fact that he's been a fairly constant main player in the show since the beginning, it took him far longer than most of the other main boys of the cast to finally appear in doll form (second probably only to Slo Mo). Even his (then unknown to be related) cousin Holt got a basic doll with a diary - with Jackson getting the doll treatment twice - long before Heath did.
Daughter of The Phantom of the Opera. First mentioned in Holt Hyde's diary, Operetta sat in limbo, aside from brief mentions in subsequent diaries until September of 2011 where she made an appearance in both illustrated and doll form on the official Facebook page before making a string of appearances in the webisodes.
American Accents: Sports a southern accent with a noticeable drawl. It's justified by Word of God as her parents moved from France to New Orleans when she was little.
Cool Pet: Daddy-o Long legs, her guitar playing pet spider.
Early-Bird Cameo: Her first mention was in Holt's diary. She's reappeared in Spectra's diary and Cleo's 2nd edition diary.
Fiery Redhead: She doesn't take well to being threatened, nor being talked about behind her back.
Good Scars, Evil Scars: Has scars along the left side of her face that she covers with a musical note mask. Apparently they go all the way down her body.
Make Me Wanna Shout: Shatters a crystal idol with her voice in "Monster Mashionals Part 2", and "Uncommon Cold" shows that even her sneezes can be supersonic.
One of the Boys: May be this, as she says her best friends are Deuce and Holt.
Ship Sinking: She went out with Holt in the diaries, but because of Holt's temper, it didn't last long.
The Rival: Cleo sees her as this when it comes to Deuce, but Operetta isn't into him.
A werecat who was introduced in the first episode of Volume 2. Tired of Cleo's perfectionist attitude, she and the Werecat Twins leave the fearleading squad, and later after seeing how well the squad is doing with Frankie, Draculaura and Clawdeen, she tries to rejoin only to be rejected by Cleo. Toralei leaks the Monster High routine to the rival, Smogsnort's Vampiric Academy, as revenge, but fails.
Alpha Bitch: And you thought Cleo was bad. Toralei manages to be worse.
Purrsephone & Meolody, otherwise also known as the Werecat Twins, largely exist as a silent girl posse for Toralei.
Always Identical Twins: Aside from the hair and their leg markings being on opposite legs. On their official artwork, their outfits are the same design, but in different colors with shoes that differ and different vest detail. Played more straight in the webisodes; they do little more than smirk at Toralei's shenanigans.
Averted in the diary. (See single-minded twins below.)
Also, for those of you that have wondered, Meowlody is the one with white hair, Purrsephone the black.
Girl Posse: To Toralei. They think of her as a sister.
Single-Minded Twins: Averted via the diary showing their differences: Purrsephone is slightly less likely to prank and has a desire to breakaway from her sister while Meowlody is much more chaotic and slightly more dominant.
Those Two Guys: Neither have spoken and they essentially serve as Toralei's cronies in the background of the webseries.
Cleo's malicious older sister who rejoices in asserting her authority over her younger sister and anyone else around. Though she's only made a brief appearance in a recent webisode, her name is trademarked, she has an official bio on the site and a doll of her was released, which means that she'll be around to stir up some trouble for a while to come.
Alpha Bitch: Even Toralei and Cleo cannot compare to Nefera's bitchiness.
Big Sister Bully: Very clearly enjoys tormenting Cleo and, based on how Cleo reacts to her, always has.
The Cheerleader: Was this during her tenure at Monster High, the captain in fact, before passing on the reins to Cleo.
Early-Bird Cameo: First mentioned in Clawd's first and Cleo's second diaries before making an appearance in the webisodes.
Establishing Character Moment: After making a grand entrance, she taunts and then blackmails her sister into doing her bidding after finding out about the party thrown behind their father's back. This is all within about ten seconds.
Laser-Guided Karma: In "Monster Mashionals Part 2" Nefera uses the family idols to get her team of fearleaders to win, but this prompts the catgirls to help Cleo as they learned their lesson from last time and wanted to win fairly this time around. Ghoulia shows Scary Murphy a video of Nefera cheating, and in turn Nefera is stripped of her previous awards, causing her to give an anguish-filled, glass-shattering scream in defeat.
Howleen is one of the many younger siblings in the wolf family and shares a room with Clawdeen. After being mentoned several times in diaries, she officially made her appearance in the second Monster High TV special Fright On. She was released as a doll in a 2-pack with Clawdeen in early 2012.
Annoying Younger Sibling: To Clawdeen, as mentioned from the beginning. Highlighted in the special with her "borrowing" several of Clawdeen's things without permission.
Rummage Sale Reject: She describes her sense of fashion as "taking lots of different styles and mashing them together to make something totally new and creepy cool". Clawdeen says it looks like she got dressed in the dark.
She Is All Grown Up: Played with. Draculaura mentions her being all grown up, as she's starting Monster High.
Sloman "Slo Mo" Mortavich
One of the zombies and Ghoulia's boyfriend. He seems to be friends with both Heath and Gill.
Hair-Trigger Temper: A mild example. He does not react well to being cheered during his chess games or to Heath's guitar playing. Being poked in the eye seems to be an exception though (at least if it's Ghoulia).
Subverted, sort of, in "Freaky Fridate," where he is accidentally body swapped with Deuce at the end of the episode. Deuce, in Slo Mo's body, but with his own voice, utters the last word of the webisode: "Cleo!"
The Headmistress of Monster High, who tries to balance doing what's best for the school, and encouraging her students to be themselves. She is often seen in the company of her horse Nightmare. Bloodgood and Nightmare had a doll release in late Spring, 2013.
Only One Name: No first name's been revealed for Headmistress Bloodgood.
Reasonable Authority Figure: Despite being strict when it comes to the rules of the school, she encourages her students to take chances and be themselves, sometimes even directly involving herself in their actions/antics.
Gillington "Gil" Webber
Son of the River Monsters. Has a loving, but troubled, relationship with Lagoona, thanks to his parents' prejudice against saltwater monsters.
Dating What Daddy Hates: Both his parents are equally opposed to the relationship. His parents even made him change schools for a time to try and break them up, but they eventually gave in and let him go back.
Only Known by Their Nickname: You won't hear him called "Gillington" much. Averted only in Lagoona's 13 Wishes diary, after Howleen's wish turns her into a freshwater monster.
Lovable Coward: shows up a few times, but mostly in the special. But when push comes to shove, he comes through.
A school bull-y. Also the son of the [[Minotaur]].
Stronger Sibling: When Frankie threatens to tell his sister Minny about his bullying, his reaction indicates that she may be this.
A raggedy doll created by Frankie to be her boyfriend. After Frankie decides that she doesn't need a guy to fit in, she tosses him away, only for him to reveal that he's alive and heartbroken at her "breaking up with him." He was made into a doll and was released in a 2 pack with Scarah Screams as the SDCC 2012 doll.
The Not-Love Interest: He slowly gets over Frankie while forming a strong bond with Scarah Screams the banshee. Peers have asked them why they aren't dating, and he admits that, while he's really close to her, he just doesn't feel any romantic attraction to her.
The daughter of Cupid, she runs the school's love advice radio show and is featured in the 2012 special "Why Do Ghouls Fall In Love?". She has a doll sold exclusively at Wal-Mart stores and was later re-released with a diary. She's been recently transferred to Ever After High.
A-Team Firing: Her freaky flaw is her seriously bad aim, which was a plot point in the special.
Foil: To Abbey. C.A. encourages people who follow her radio show to flirt and laugh at the other person's jokes even if they aren't funny, while blunt, outspoken Abbey says they should just be brutally honest.
Happily Adopted: Reveals this in an interview with the official Monster High Tumblr. Her true monster heritage is unknown to everyone, herself included.
Overly Long Name: Alludes to this being the reason that she goes by C.A.: "I use my initials because my name is scary long, hideously unpronouncable and you know you're just going to call me 'Cupid' anyway."
Confirmed in the diary, where we learn that it stands for Chariclo Arganthone.
Smitten Teenage Girl: In her diary, she develops a crush on Deuce after he accidentally runs into her and, after getting his sunglasses knocked off, explains that his stone gaze does not work on gargoyles and basilisks. She knows that Deuce and Cleo are an item, but this does not stop her from getting her pet, Roux, to steal Deuce's casketball in order to lure Deuce to her. Though nothing more than talking occurred between Deuce and herself, Rochelle does admit to feeling somewhat guilty afterwards.
Your Cheating Heart: Had that crush on Deuce despite having a boyfriend waiting back home for her. Justified in that said boyfriend had just stopped writing her with no explanation what so ever, so for all she knew, he had just dumped her.
Jedi Mind Trick: She can use her "Power of Pollen Persuasion" to get others to do her bidding. However, she can only affect one monster at a time. (Unlike Poison Ivy, this works on all monsters, not just ones attracted to her.)
April Fools' Day: Mattel released the profile information for Invisi Billy as a teaser for his soon-to-be-released doll... on April 1st. Complete with a full package mock-up of an empty box, with the box quote, "How do you know I'm not in the box?"
Daughter of the Boogeyman. First appears in the 13 Wishes CGI special.
Amazing Technicolor Population: A unique example, even in Monster High; she appears to have grey or blue-grey skin, with darker grey designs or tattoos around her hands and feet. In many photos, her face also appears to be more blue than the rest of her body.
Cool Loser: She considers herself a misfit and an outcast, but is perfectly fine with it.
Dream Stealer: A rare good example, as she hides under normie beds to take their nightmares and eat them, rather than adding to them like her father.
Daughter of the Arachne.Was one of three to win the fan vote for which dolls will be made in 2012. A prototype of her doll was previewed at San Diego Comic-Con International 2011. Despite placing second, Wydowna was made a character in 2013. She plays a villainous role in the Polterghoul's story.
Karma Houdini: Arguably. Howleen figures out exactly what's been driving her for all these years and arranges for her to trade places with Gigi as the new Genie of the Lamp, which is exactly what both of them really wanted.
Living Shadow: She becomes visibly more "real" as the Finder — in this case, Howleen — makes her kind of wishes and grants her more control.