Here's a Character List of People who've physically appeared in the story by chronological order (and are probably of some importance).
It's not necessary to read, but you just might get a cookie if you read through it, yeah?
It'll update with the story.
Vernon Dursley – Our story's Hero. Not really, but can we give him a hand for putting up with all this nonsense? I mean, all he wants is his normal boring life back. You'd think that wouldn't be too much to ask. You'd be wrong. He doesn't have a special ability because normal people don't have special abilities. How rude of you to assume otherwise.
Petunia Dursley – Surprisingly, she is quite happy she never got dragged into all this magic nonsense. She knows exactly what it does to people and she's perfectly happy the way she is, thank you very much. Her special ability is Denial.
Dudley Dursley – The only son of the Dursleys, this tragic young man goes through life knowing the horrors of his eating disorder. But being unable to control the impulses from his brain he is forced to watch helplessly as his body consumes more than twice his weight on a daily basis. Magical therapy could easily fix it, but wizards are jerks. His special ability is Shortness of Breath.
Albus Dumbledore – The Headmaster of Hogwarts and, as many will tell you, the only person You-Know-Who feared. In his greatness, however, he often finds himself wondering just where he is and who stole his horse. His special ability is something you'll learn when you are older and ready.
Minerva McGonagall – Deputy Headmistress of Hogwarts. And with someone like Albus as the Headmaster, she basically keeps the place from becoming bankrupt. Having long since lost her admiration for Albus and enthusiasm for working with him, it's all she can do to keep herself from just running away. Her favorite ability is to sleep for twenty hours straight, wake for four hours, and do it again. (Weekends only, of course.)
Rubeus Hagrid – A lovable, walking, security leak, Hagrid couldn't keep a secret to save his life, which actually happened once. His first name sounds yummy. His self-proclaimed ability is Baking.
Harry Potter – Our story's unwilling Hero. (No really, he is, even if he is several characters down this list and constantly questioning his identity.) And as every Hero, he must embark on a journey full of people wanting him to do things they can't be arsed to do themselves. Like saving the world. Is it any wonder he would like nothing more than to just run away and live somewhere else? His special ability is to Win when confronted with the Enemy.
Piers Polkiss – A boy with a high pitched voice. The church keeps trying to recruit him because he doesn't need to be a eunuch to achieve such a wondrous singing voice. His special ability is Whine.
Arabella Figg – . . . Who were we talking about again?
Tom (Landlord/Barkeeper) – He owns the Leaky Cauldron by day and makes a killing off illegal gambling by night. He's probably ex-Mafia. His only ability is to Shoot Troublemakers in the Head.
Dedalus Diggle – He went into hiding after that traitor Bucket took over his factory and changed it to the name Nestlé. Now he helps out his fellow crazy, Albus Dumbledore, as he plots his revenge on the Bucket family. His special ability is Founder's Grudge.
Quirinus Quirrell – It's a long way down for someone who once stood at the pinnacle of Defense Against the Dark Arts research. Suffering from schizophrenia and likely had a stroke in the past, he now struggles to make a living as a teacher. However, the subject that was once his love and joy has now become somewhat of a joke to the students as they shamelessly ridicule his disabilities. It's a tragedy he was possessed, really, the generation lost a brilliant mind. Too bad no one could tell the difference. His special ability is Ashes to Ashes, Dust to Dust.
Griphook – Disgruntled. Along with the rest of the Goblin nation, he rakes in cash by overcharging ignorant Pureblood wizards. Unfortunately, some of that goes into hush money to prevent Muggle-born wizards from revealing the truth. His special ability, as well as that of most goblins, is Bribe.
Madam Malkin – Living out her dream of putting children in dresses. Responsible for the ridiculous style of clothing most wizards and witches seem to prefer. Her special ability is Effeminate (yes, that's a verb).
Draco Malfoy – Resident beautician and fashion expert. He hopes that one day Harry will see him and return his love. He thinks that living in Slytherin is rather icky and the dungeons are in sore need of a makeover. His ambition in life is to be a bride. His super fabulous ability is Hair Care.
Garrick Ollivander – Time traveler who gets his kicks by messing with people's minds and telling them wild stories about what owning particular wands means. He may or may not own a phone booth. His special ability is Paradox Aversion.
Hedwig – A bit protective of Harry, she's just an ordinary owl. Yup. Just a common snowy owl with average intelligence and in no way could be an immortal demon from beyond the Void. Her very normal, totally commonplace ability is Bite.
Molly Weasley – Doesn't do subtle. Her special ability is Smother. (Warning: only effective on children and former Army members who may or may not go on to become psychotic, nationalistic dictators)
Fred and George Weasley – Surprisingly normal in comparison to the rest of the people in this story. Their special ability is Telepathy.
Ginny Weasley – She just can't figure out what kind of character she wants to be. One moment she acts like Harry doesn't exist, the next she's threatening to commit a murder-suicide. Her special ability is Tailing, no, not Stalking.
Ron Weasley – Kind of a jerk. Likes food. To be honest, he doesn't really care about much else. If it weren't for the potential to follow Harry to some expensive dinner parties in the future, he probably wouldn't have bothered being friends with him. His special ability is Hungry, Hungry Hippo (Very Hungry).
Neville Longbottom – The son of Frank and Alice Longbottom, he's too cool for the likes of you. His special ability is Intimidate, followed by Physical Violence. Yes, he gets two because he's that cool. Perhaps he's the reason you don't have a special ability yourself.
Trevor – A poisonous dart frog. Highly dangerous, it's a bit of a mystery how Neville was allowed to bring the tiny colorful amphibian. Then again, Neville Longbottom doesn't have time for your rules, man. His ability is Being Himself.
Percy Weasley – The self-proclaimed voice of reason. This tends to boil down to making things up as fast as possible to keep the craziness around him down to a manageable level. Sadly, this makes him seem a bit strange as well. His special ability is Conspiracy.
Hermione Granger – She hates stupid people. Hence, she hates most of the wizarding world and is secretly plotting to take over one day. Saying she's a bit sadistic is like saying Ron is a bit hungry. Her special ability is Domestic Violence.
Vincent Crabbe – Draco's bodyguard. He has a near genius-level IQ and probably belongs in Ravenclaw. This goes to waste as he is being paid good money to be Goon #1 by Lucius Malfoy. His hired ability is Threaten.
Gregory Goyle – Draco's bodyguard. He enjoys team sports and probably belongs in Hufflepuff. He is also in Slytherin because Lucius Malfoy paid the Sorting Hat a lot of money to keep his son's bodyguards with him. His hired ability is Threaten.
Argus Filch – Caretaker of Hogwarts, he gives the impression he's simply serving time through community service. What his crime was, nobody knows except for Albus Dumbledore, who likely forgot it five minutes after allowing Argus to do his community service at Hogwarts. Being a squib, he cares not for the matters of wizards despite having the ability to fend off Death Eaters without breaking a sweat. His single target of care and protection is his pet, Mrs. Norris. His state-approved ability is Sweep.
Fat Friar – Resident ghost of Hufflepuff. Despite being a devout follower of Christ, he regretting dying a virgin and thus has a lot of pent up frustration. He doesn't do much aside from yell at various schoolchildren. People wonder why he was so well received in his time. His anointed ability is Compel.
Nicholas de Mimsy-Porpington – Resident ghost of Gryffindor. Some idiots were too lazy to do his execution properly and instead tied him to a rock and let the village idiot stab him in the neck repeatedly with a spoon. It was all quite horrific, really. Hundreds of people flocked to see the execution. He is, therefore, probably the only ghost closest to the traditional horror associated with ghosts. His special ability is Terrify.
Bloody Baron – Resident ghost of Slytherin. An impatient man, he was driven to insanity when Helena Ravenclaw said "Just one more minute" one too many times. In his frustration, he realized it was a waste of time to wait for death and killed himself as well. He's not the smartest of people, to be honest. His special ability is Bleed.
Helena Ravenclaw – She hates people. No seriously, she does. After being killed for no apparent reason, she realized there was not much of humanity worth appreciating. Realizing Tommy wanted to go out and kill people, she happily showed him where her mother's Diadem was, hoping he'd go out and thin the population. And go out he did. Her special ability is Violence. Yes, straight up Violence.
The Hat – Slum drunk. Kind of an ass. Three hundred and sixty-four days of nothing every year has turned this once intricate and one-of-a-kind piece of spellwork that borderlines human intelligence into a raging, cynical alcoholic. Having been technically alive for close to a millennium, he's gained the understanding that people really don't change and does everything he can to convince the children of that. Students frequently have to see Madam Pomfrey for counseling after their sorting. His special ability is You Can't Handle the Truth.
Hannah Abbott – A meek little girl who's probably too trusting of people. She'll probably shed all that once she goes under the tutelage of Old Man Tom. Her future ability is to Shoot Troublemakers in the Head. Fancy that.
Susan Bones – An ambitious and loyal girl who wants to be like her no-nonsense Aunt, even if she wouldn't hurt a fly. No worries, a healthy dose of Cynicism will take care of that. Her future ability is Execute.
Terry Boot – Boring kid who is smarter than the average shmuck. Maybe one day his love for books will let him help out the Main Characters. His boring ability is Read.
Mandy Brocklehurst – Practically nonexistent. Her unknown ability is Disappear.
Lavender Brown – Girls just wanna have fun. She's secretly best friends with Draco Malfoy. They frequently trade fashion tips. Her special ability is Perfect Makeup.
Millicent Bulstrode – A generally nice girl with a rather mean streak if you make fun of her size. Her goal in life is to become a Heroine and punch a dragon in the nose. Her special ability is Brawl.
Justin Finch-Fletchley – Poor boy, he never stood a chance. His only mistake was giving up his Oxford track to learn magic of all things. His special ability is Bitter Regret.
Seamus Finnigan – A drunken Irish, which in itself is somewhat redundant. *Dodges thrown objects* Yes, good ol' Seamus had his first taste of Guinness at the tender age of two. His parents realized it was quite easy to prevent liver damage when one has access to magical medicine and they've been on a constant bender ever since. Seamus hates Hogwarts because they won't serve alcohol to 'minors'. His special ability is Inebriation.
Morag MacDougal – Lost in the sands of time. Her special ability is Low Profile.
Lily Moon – Actually Luna Lovegood. She came to Hogwarts a year early because she was curious about school life. Her father barely noticed her disappearance and subsequent reappearance. He didn't even notice she already had most of her school books for her official Year One. Her omniscient ability is Fourth Wall.
Theodore Nott – Kind of a follower. He just goes with the flow in Slytherin, really. His special ability is Taunt.
Pansy Parkinson – Surprisingly innocent. Like Draco, she also wants to be a bride when she grows up. Her special ability is Pout.
Padma Patil – The brainy one. Surprisingly, she pulls off Weasley-level shenanigans with her sister, usually in the form of switching uniforms and pretending to be the other. Her special ability is Swap.
Parvati Patil – The sexy one. But sometimes she just wants to do a bit of reading, hence the switching. Her special ability is Swap.
Sally-Anne Perks – A nonessential character. Unfortunately, these kinds of characters tend to vanish if you take your eyes off them. You know, the kinds of people who wander off into the wilderness and get eaten by monsters fifty to a hundred times their measly base level of 1? In her case, it was probably an acromantula. Her special ability is Respawn.
Dean Thomas – Cool guy, real chill. Not a whole lot bothers this dude. His special ability is Chillax.
Lisa Turpin – The epitome of academics. She seeks knowledge for the sake of knowledge, making her a great researcher, but a poor conversationalist. Her somewhat normal ability is Research.
Blaise Zabini – Taking lessons from his mother at an early age, he knows that the quickest way to make lots of money is to woo a bunch of older women and inherit their money when they die. He's a rather cynical kid. His special ability is Woo.
Filius Flitwick – Never really lost his goblin roots. He puts on the squeaky professor act as his normal voice terrifies children. His special ability is also, unsurprisingly, Bribe.
Peeves – A bound evil spirit that pretends to be some kind of wish-granting genie. After the first dozen deaths and disappearances way back in the eleventh century, students were told that under no circumstance should anyone accept his offers for that was the only way he could cause hard to an individual. While he mellowed out over time, he still tries to collect a soul here or there. His special ability is Soul Harvest.
Mrs. Norris – A nundu kitten. Most people think she's a full grown cat because of her size. Argus does a very good job at hiding this fact. Her special ability is Plague.
Severus Snape – Definitely a jerk. He hates everyone with equal prejudice. He thinks Harry is an idiot and knows Dumbledore is totally, definitely not-senile. If alcoholism didn't remind him of his deadbeat dad, he would've become one himself long ago. His well honed ability is Turncoat.
Fang – According to Hagrid, just feeling a little under the weather. According to everyone else, a zombie dog. Surprisingly sentient and seems to enjoy his un-life quite a bit. His special ability is Drool.
. . .
Extras (People who are definitely of no importance):
Man in the Yellow Dress/Robes: Universal punching bag. He's got a broken nose. Wonders why people trample over him so much.
Old Man: Can refer to several old men. Or maybe they're all the same old man. Whatever the case may be, they're all likely senile. Maybe they're all Dumbledore . . . think about that.