Professor McGonagall stands firm as the Deputy Headmistress of Hogwarts. A resolute and stern woman who nonetheless places her value in forthrightness and propriety. Very befitting of her role as Head of Gryffindor House. Played in the films with tremendous faith to the books by Dame Maggie Smith, she is instantly relatable. We've all at some point had that teacher who was tough to the point of getting into arguments, but ultimately fair.
Few characters at Hogwarts can ruin someone else in so few words and with such dry wit. She can also rage out when called for. We're using both the Harry Potter movies and books to get the best of the best from Gryffindor's Head of House.
Giving The Dope Some Rope
In The Chamber Of Secrets, Gilderoy Lockhart's frequent boasts and inflated sense of grandeur finally get their comeuppance from the biting tongue of McGonagall. As the 'Monster Of Slytherin' problem reaches its zenith, McGonagall calls Lockhart's constant bluffs in front of everyone.
“We’ll leave it to you, then, Gilderoy,” said Professor McGonagall... We’ll make sure everyone’s out of your way. You’ll be able to tackle the monster all by yourself. A free rein at last.”...
“Right,” said Professor McGonagall, whose nostrils were flared, “that’s got him out from under our feet.
Minerva is not one to suffer fools, and here she deftly removes one so the real problem can be attended to.
Tardy Potter
McGonagall runs a tight ship and expects her students to arrive on-time for her Transfiguration lessons. When Harry and Ron are unable to match her punctuality expectations, they're greeted with this succinct assessment.
"Perhaps it would be more useful if I were to transfigure Mr. Potter and yourself into a pocket watch? That way one of you might be on time... Or perhaps a map?"
Without going overboard she instills into the boys their expected duty. It's one of McGonagall's great and indelible attributes that she maintains fairness even when remonstrating.
Prideful Pussycat
As one of only 7 'recorded' Animagi during the 20th Century, McGonagall holds rare distinction. With that, it's fun to see her show a moment of pride in her skills for once.
“Really, what has got into you all today?” said Professor McGonagall, turning back into herself with a faint pop, and staring around at them all. “Not that it matters, but that’s the first time my transformation’s not got applause from a class.”
The class is too preoccupied with the Chamber Of Secrets to give her the adulation she feels is due. It's a rare glimpse beyond the veil of her teaching that humanizes her. But not the last...
The Divination Divide
McGonagall has a healthy skepticism with fortune-telling and predicting the future. That comes out in her frequent bone-dry comments towards Hogwarts Professor of Divination, Sybill Trelawney.
After Trelawney 'predicts' Harry's imminent death by Grim.
“You look in excellent health to me, Potter, so you will excuse me if I don’t let you off homework today. I assure you that if you die, you need not hand it in.”
At Christmas Lunch,
Where is dear Professor Lupin?” (Said Trelawney)
“I’m afraid the poor fellow is ill again,” said Dumbledore...
“But surely you already knew that, Sybill?” said Professor McGonagall, her eyebrows raised. Professor Trelawney gave Professor McGonagall a very cold look.
“Certainly I knew, Minerva,” she said quietly. “But one does not parade the fact that one is All-Knowing. I frequently act as though I am not possessed of the Inner Eye, so as not to make others nervous.”
“That explains a great deal,” said Professor McGonagall tartly.
Quidditch Commentator Qualms
One of the few places where McGonagall's lack of judgment results in constant hilarity at her expense.
“Jordan, would you mind telling us what’s going on in the match?” interrupted Professor McGonagall’s voice.
“Right you are, Professor — just giving a bit of background information — the Firebolt, incidentally, has a built-in auto-brake and —”
“Jordan!”
“… but now that big Hufflepuff player’s got the Quaffle from her, I can’t remember his name, it’s something like Bibble — no, Buggins —”
“It’s Cadwallader!” said Professor McGonagall loudly from beside Luna. The crowd laughed.
Teaching Through Terseness
McGonagall has virtually no leeway when it comes to excuses. In her class, you're either acceptable or being cleverly reminded via chiding that you need to pick your wand-game up.
“Maybe not, Thomas, but believe me, you need all the preparation you can get! Miss Granger remains the only person in this class who has managed to turn a hedgehog into a satisfactory pincushion. I might remind you that your pincushion, Thomas, still curls up in fright if anyone approaches it with a pin!”
“Your grandmother sent yours (Hogsmeade permission) to me directly, Longbottom,” said Professor McGonagall. “She seemed to think it was safer."
Dame Of The Dance
One of the scenes that both leaped off the page and filled theaters with laughter was McGonagall insisting upon the traditions of the Yule Ball during the Triwizard Tournament. Dame Maggie Smith took that liberal chance to have us in stitches.
“Dance partners?” He felt himself going red. “I don’t dance,” Harry said quickly.
“Oh yes, you do,” said Professor McGonagall irritably.
"Godric Gryffindor has commanded the respect of the wizarding world for nearly ten centuries. I will not have you, in the course of a single evening, besmirching that name by behaving like a babbling, bumbling band of baboons."
"Mr. Weasley, will you join me please. Now, place your right hand on my waist."
"Where..?!" splutters Ron.
"My waist.."
She doesn't show it, but you get the distinct impression she's thoroughly enjoying toying with the boys' reluctance to dance.
Mischief Managed
After 5 books knowing McGonagall's aversion to rule-breaking, it is doubly funny when she employs tactics she'd usually be against. Especially when involving the perpetual pest, Peeves.
Harry witnessed Professor McGonagall walking right past Peeves, who was determinedly loosening a crystal chandelier, and could have sworn he heard her tell the poltergeist out of the corner of her mouth, “It unscrews the other way.”
The Headmistress Of Hogwarts
When everything comes to a head in the seventh book (and 8th film) McGonagall steps to the fore. Assuming her rightful place as Headmistress and dishing out these pearls of wisdom.
“I think so,” said Professor McGonagall dryly, “we teachers are rather good at magic, you know.
“Our headmaster is taking a short break,” said Professor McGonagall, pointing at the Snape-shaped hole in the window.
"Where's Professor Snape?" shouted a girl from the Slytherin table.
"He has, to use the common phrase, done a bunk." replied Professor McGonagall and a great cheer erupted from the Gryffindors, Hufflepuffs, and Ravenclaws.
An Old Softie
Toughness tempered with fairness and a soft spot for good deeds and those who strive for them. That is another McGonagall trait that makes her invaluable to the faculty and students of Hogwarts, and there are multiple times in the book and film where we get to see this softer side shine through.
For Lupin and Tonks potential relationship:
“Dumbledore would have been happier than anybody to think that there was a little more love in the world,” said Professor McGonagall curtly
For Hagrid's input, once she found herself in charge at Hogwarts:
“Professor Dumbledore always valued your views,” said Professor McGonagall kindly, “and so do I.”
When Neville's Gran is pressing him
“My grandmother thinks Charms is a soft option,” mumbled Neville.
“Take Charms,” said Professor McGonagall, “and I shall drop Augusta a line reminding her that just because she failed her Charms O.W.L., the subject is not necessarily worthless.”
and lastly, when she finally gets to use that spell.
"I've always wanted to use that spell!"
...It's much more impressive in the film.