Was Barty Crouch Jr. really scared of being sent to Azkaban or were these Crocodile Tears to gain sympathy from the jury? Perhaps a mixture of both? Also was he truly a loyal servant to Voldemort or did exposure to the dementors/years of being under the Imperius Curse delusion him into thinking so?
There's also Ludovic Bagman. Was he truly an innocent person who was tricked into passing information to the Death Eaters or did he do so willingly? If the second interpretation is true, was he simply an informant or was he himself a full blown Death Eater?
Crazy Awesome: Alastor Moody and his violent dustbins. They don't call him "Mad-Eye" for nothing.
Draco in Leather Pants: Barty Crouch Jr. While it is true that he was neglected by his father, this still doesn't excuse joining the ranks of a terrorist group that killed hundreds of innocent people. Many fans however seem to differ.
Fanon: Despite his role as a Red Herring in this book many fans believed Ludo Bagman to be a Death Eater or at least a supporter. Despite his Chuck Cunningham Syndrome for the rest of the series, this theory is still fairly common.
Ron notes Percy's inability to recognize a joke. Cut to Deathly Hallows where Percy shows he does recognise and can tell a joke right before Fred is killed.
At one point in the book, Fred and George tell their angry mother that if she yells at them now and the Hogwarts Express crashes tomorrow, that'll be the last thing she ever said to them. In context, it's pure Black Comedy (even to Molly), but a year later we find out that Molly's biggest fear is losing her family. Worse in Deathly Hallowssee above spoiler.
Dumbledore's remarks about Aberforth to Hagrid, notably his comment that he's "not entirely sure he can read", are amusing at the time. When, in DH, we learn about the estrangement of the two brothers, and the extent to which Albus' intelligence helped to contribute to that situation, it appears a considerably more mean-spirited thing to say.
Fred and George becoming old due to the potion failing. This is the only time the two will grow old together.
Early on in the book Moody's offscreen Establishing Character Moment is an amusing story about commotion in his backyard - with him apparently jinxing dustbins. We later find out this was actually Barty Crouch Jr attacking him so he could impersonate him for the year.
Genius Bonus: The Durmstrang Institute's name is a spoonerism of the German phrase Sturm und Drang, the name of an 18th century Proto-Romantic literary movement known for its glorification of subjective human emotion and experience over the cold rationalism that characterized the Enlightenment. It's a fitting name for a Scandinavian school for wizards, which teaches Magic that that can't necessarily be understood rationally. Particularly since the most famous Sturm und Drang participant was Johann Wolfgang von Goethe, the author of Faust—a play about a German mystical scholar who dabbles in the Dark Arts in his quest for knowledge.
Both Harry and Cedric are initially outraged that the Quidditch pitch has been turned into a maze for the third task; they're assured that they'll have their pitch back once the task is over. Cedric never gets to see the Quidditch pitch back to normal, since he is killed by Voldemort and Wormtail during the Task.
Petunia is described as looking out the window "as though there had been a warning about an escaped rhinoceros." In Fantastic Beasts and Where to Find Them, Newt Scamander has to recapture his escaped erumpent, which strongly resembles and harasses a rhinoceros that is trying to escape a zoo to get away from it.
This: "Dragons! ... Last year dementors, this year dragons, what are they going to bring into this school next?" Fans all know by now that the next year sees something far worse than any of the above: Dolores Umbridge as The Tyrant Taking The Helm.
The whole fact that Harry's incredibly handsome rival Hogwarts champion is played in the movie by future Edward Cullen. And really, the rivalry between Harry's supporters and Cedric's supporters could easily be compared to the Fandom Rivalry between Harry Potter and Twilight — particularly the way in which Harry and Cedric (a.k.a. Daniel Radcliffe and Robert Pattinson) are nothing but civil to each other while each has fans who volatilely bash their hero's rival. It doesn't help that Cedric first makes an appearance by jumping out of a tree. Maybe, he was bothered? His ghost is also sparkling.
Ron asked his future sister-in-law to the Yule Ball.
It's now almost impossible to watch the reaping... er, choosing of the teenaged contestants in a deadly tournament without thinking, "May the odds be ever in your favor" as their names are called out.
Overlapping with Harsher in Hindsight: Filch putting on music as Professor McGonagall dances with Ron can remind many of Walder Frey (portrayed by David Bradley) ordering to play "The Rains of Castamere" during the Red Wedding.
The fans' uproar over Hermione wearing pink instead of blue to the Yule Ball. Fast forward to Ballet Shoes where a small fuss is made over Pauline (Emma's character) getting a blue gown for a premiere. So fans finally get to see Emma wearing blue at a formal occasion. And then she stars in Beauty and the Beast (2017) as a heroine whose dress is iconically blue - and this time in the She Cleans Up Nicely moment the dress stays the same colour as it was in the original.
It's offhandedly mentioned that the pub in Frank Bryce's village is called the Hanged Man.
Idiot Plot: The only reason given for Harry participating is to lure out whoever put his name in the Goblet; he wasn't interested in participating. None of the staff of Hogwarts or Harry's friends (ostensibly both interested in his welfare) suggest he do anything other than walk into an incredibly obvious trap. The phrase 'binding magical contract' is used, with unspecified penalties for defaulting, but nothing (except the plot) prevented Harry from making an absolute-minimum pro forma effort that wouldn't risk his life. Which would have destroyed the villains' plans utterly.
I Knew It!: Not many people were surprised to find out that Snape was once a death eater.
Launcher of a Thousand Ships: Continuing the series tradition, the introduction of new characters as well as already existing ones being made prominent created some new ships, including Harry/Cho, Cedric/Cho, Harry/Fleur, Ron/Fleur, Hermione/Krum, Hermione/Cedric, Krum/Fleur, Cedric/Fleur.
Magnificent Bastard: Voldemort and Barty Crouch Jr. With the information coerced from Bertha Jorkins about a month before the actual event, Voldemort was able to concoct a plan to not only seize Harry Potter's blood and use it for his revival, but recruit a Death Eater that was long since believed dead. Barty Crouch Jr. not only successfully escorted a Book Dumb 14-year-old through a dangerous tournament designed for 17-year-olds, but did so without drawing any suspicion to himself, disguised as the Death-Eater-hating Auror himself. Not only that, but even though Harry escaped Little Hangleton, the plan Voldemort came up with made sure that the wider wizarding world didn't believe his comeback until a year later: not the success he envisioned, but still incredibly useful.
Moment of Awesome: Several, though one of the many mentions goes to the ending, where Fred, George, Harry, Ron, and Hermione all jinx Malfoy, Crabbe, and Goyle with every spell they know.
Nightmare Fuel: Rowling was apparently surprised that the editors didn't object to Voldemort's resurrection scene, specifically Voldemort's fetus-like rudimentary body.
The film has some immense fun with this, having the build up to Voldemort's resurrection very unnerving, especially when he finally reborn. His appearance of being frail-like and no nose and opening his eyes being snake-like to normal makes it more creepy.
Wormtail cutting off his own hand.
The trial of Barty Crouch Jr, with Junior begging and crying for mercy and Senior showing no emotion or connection towards his son until he finally loses it and screams at him that he has no son. YMMV, since at the end it's revealed that Crouch Jr. might actually have already beem evil and guilty, though his story still is tragic. Also, the torture of Frank and Alice Longbottom.
For those with a fear of deep, dark water, the Second Task as a whole.
No Such Thing as Bad Publicity: This entry brought the Moral Guardians out in full force against the series, ensuring this trope occurred. While still a good book in its own right, it wouldn't have been nearly as successful without all the parents, politicians, and preachers decrying it for converting children to witchraft and Satanism. Some held burnings of it. This required them to buy copies to burn them.
Barty Crouch Jr. is generally agreed by fans to be one of the (if not THE) best villains in the series. Too bad we only truly see him for a few pages undisguised (where most of his characterizations would actually apply to Moody) before he suffers a Fate Worse Than Death.
Pandering to the Base: A minor example, as this was the first book written after the series became big in America, and got Rowling deluged with questions about how to pronounce Hermione's name (it was also before the films started). So the scene where she tries to teach Viktor Krum how to pronounce it was intended directly for her new American fans.
Ron the Death Eater: Barty Crouch Sr. is often vilified to an extreme degree. While he was a Knight Templar and not a great parent, he was still on the side of the good guys and vital in defeating Voldemort's forces.
Ship-to-Ship Combat: Also, continuing the series tradition, the supporters of the new and already established ships took all new offensives for their pairings.
They Wasted a Perfectly Good Character: This book is known for the vast amount of characters revealed and introduced (far more than any other book in the series), many of which were Put on a Bus or Killed Off for Real by the end. Examples include Barty Crouch Jr, Ludo Bagman, Igor Karkaroff, Olympe Maxime, Barty Crouch Sr, Viktor Krum, and Charlie Weasley.
Unintentionally Sympathetic: Barty Crouch Jr. He lived a miserable life, trying to gain his father's approval. Then, after failing to do so, he decided to find Voldemort. Afterwards, he got thrown in Azkaban, smuggled out after suffering a year of torment from the Death Eaters, and had been put under the Imperius Curse by his own father. Watching him beg for mercy at his own trial can be heart wrenching for some, even after we find out that he was guilty for using the Cruciatus Curse (or, at the very least, just simply watching it being cast by someone else). When he's caught and forced to tell everything to Albus Dumbledore and Cornelius Fudge, he soon receives the Dementor's Kiss. Can be very sad for some to read. Not to mention, he also believes that Death Eaters that abandoned Voldemort should be punished, which shows that he does understand love.
Unintentionally Unsympathetic: Barty Crouch Sr. He neglected his son and only cared about his job. He eventually threw his son in Azkaban. Though he was right to throw him in, he also threw Sirius Black in Azkaban, who was framed for the death of Harry Potter's parents, without even giving him a trial. Afterwards, he smuggled his son out of Azkaban and put him under the Imperius Curse and later used a memory charm on someone that found out what he was doing to his son, which caused permanent brain damage on that person. The fact that he called his son out for using the Cruciatus Curse, which is one of the three unforgiving curses, proves that Barty Crouch Sr. is a hypocrite, which makes him more of an asshole victim when he's killed by his own son. Moreover, heís likely solely responsible for the Fanon perception that the Wizarding World, even excluding the Death Eaters, is socially backward to the point of medievalism, since he not only threw Sirius in Azkaban without trial, but didnít recuse himself at his sonís trialó-something which would be required by law in Muggle society.
The Woobie —> Jerkass Woobie: Barty Crouch, Jr. When we first see him, he is pleading for mercy as his own father disowns him in public and orders him thrown into Azkaban. Unfortunately, it then turns out his father may have been right, as Crouch Jr. turns out to have become a fanatical Death Eater who might have tortured Neville's parents into insanity, rather than being Wrongly Accused as assumed.
Harry gets hit with this earlier in the book: After being chosen as Champion his life quickly goes to crap: The other three houses turn against him, believing he put his name in to snatch more glory for himself and even Ron buys into this. This image isn't help by Rita Skeeter's article glorifying Harry using mostly made up garbage, which causes Harry to snap at his crush Cho and only drives a further wedge between him and Ron. Oh and on top of all of this he has to fight a ferocious dragon with only a day to prepare. All for an honor he didn't want and would gladly give up if he could.
YMMV tropes present in the film:
Big-Lipped Alligator Moment: Harry finding Crouch Sr's body. The scene comes apropos of nothing, has nothing to do with the story anymore, and is never brought up. Harry doesn't even tell Dumbledore about it like he planned. The scene just comes out of nowhere, happens, does nothing to the story, and then is never discussed ever again. Even the mood doesn't fit. A deleted scene helps to bridge it with the next scene better, however.
Harsher in Hindsight: After their failed attempt to put their names into the Goblet of Fire, Fred and George get into a fight and one of them can be heard saying "I'll tear your ear off!" to the other. George ended up losing an ear three books later from a Death Eater.
He Really Can Act: Harry's complete breakdown after he arrives back at Hogwarts with Cedric's corpse along with the news that Voldemort has returned.
Robert Pattinson gets some love for his performance as Cedric, way before he did Twilight, being a lot more of a Nice Guy to Harry compared to his role in in the Twilight movies. His tragic death made it a lot more of a solidification.
Memetic Mutation: Slight one. Fans will lash out at Voldemort and Wormtail for killing Cedric, not just because of obvious reasons, but because it locked Robert Pattinson out of the series and led to him being cast in Twilight.
"He asked calmly." Explanation An excerpt from the book right after Dumbledore's "Did you put your name in the Goblet of Fire?" line, said in mockery of film Dumbledore's decidedly not calm delivery of this line.
Harry's sassy response to Neville talking to him about plants in the film, "No offense, but I really don't care" is a rather popular GIF.
Narm Charm: Although the She Cleans Up Nicely scene has its share of Narm, the shot of Hermione nervously peaking out from behind the wall and descending the stairs is still rather cute - especially for the Adorkable expression on Emma Watson's face.
Never Live It Down: Even to this day, many detractors of Michael Gambon as Dumbledore point to the "HARRYDIDYEPUTYERNAMEINTHEGOBLETOFFIYAH?!?!?!?" scene as an example of why they think he was a bad choice despite the fact that this was the only film where he was portrayed this way.note Even in the same scene, his asking Harry that he's "absolutely sure" is far more in-line with the character, making the entire interaction come across as Anger Born of Worry.
Squick: "Mad-Eye Moody" transforming back into his true form, Barty Crouch Jr. Moody should be missing an eye (hence the magical prosthetic), so it means that when Barty Crouch starts his entire ruse, he has to voluntarily lose one of his own eyes in the transformation. There was even a moment where "Mad-Eye" is desperately reaching for the belt that holds the magical eye to take it off, because Crouch's eye is growing back once the Polyjuice Potion wore off, and the magical eye is most likely "fighting for space".
They Changed It, Now It Sucks!: Showing how some fans can take this trope to the extreme, one of the biggest complaints about the movie? Hermione's dress for the Yule Ball. It's blue in the book but pink in the film. There were thousands of complaints, even with the film's IMDB page in an edit war over listing "Hermione is a person who hates pink and would never wear a pink dress" as a Plot Hole. note The costume designer said that blue was the original choice but that it simply didn't look good on Emma Watson. Here◊ is an edit of Hermione in the blue dress for reference. It's worth noting that the rest of them didn't wear the colours they had in the book for the film either - Harry went from green to black, Parvati went from pink to orange and Padma went from turquoise to pink. As for Hermione "hating pink", she's mentioned as wearing a pink dressing gown in the first book.