Artemis starts out this way, being loath to actually kill anyone (fine with kidnapping, psychological warfare and an occasional bomb or two, though), and very cordial with the negotiators, as well as keeping his words. Also while he is not exactly good, he does care for his allies and family.
"... every inch the gracious host, albeit a sinister, evil, determined one."
Faux Affably Evil: Turnball Root, who compliments Holly right after kidnapping her. He doesn't really care about anyone except for his human wife Leonor (and even then he kept her in thrall so that she wouldn't ever think of leaving him) and is willing to kill his own trusted lackey if needed without a hint of remorse.
Air-Vent Passageway: in The Arctic Incident. Artemis has to crawl through a duct filled with fuel for the building's plasma weapons. Before his helmet runs out of air. Without being able to see where he's going. Knowing full well that if anyone turns on the plasma cannons, he's toast. Not to mention that once he gets out, he has to be sprayed with anti-radiation foam or he'll likely develop cancer.
All Trolls Are Different: In this case, ten-feet-tall gorilla-ish tunnel-dwelling monstrosities with poisonous tusks. And dreadlocks.
Always Chaotic Evil: Goblins and trolls, although the latter are mostly portrayed as just animals, and the former is incredibly, incredibly stupid. They're directly stated to be as smart as rats.
Strangely averted with the demons, as only Leon Abbot is shown to be actively evil and willing to use magic to brainwash others.
Amnesiac Dissonance: An odd case. After recovering from his mind-wipe, Artemis sees that he was regressing to his old criminal ways, as he had predicted he would. After all, his character growth was a result of his experiences with the People...so removing all memory of his experiences with them takes away all the good it did him. Holly is visibly nervous when he brings this up because she knows how terrifyingly amoral he used to be.
Amnesiac Resonance: After Artemis's mind-wipe, he admires a painting, The Faerie Thief. He acknowledges that the fairy in the painting can't enter a human dwelling without permission (one of the laws fairies live by), then wonders how and why he knew that. Later, when an assassination attempt against him fails, he recognises the blue light from the incident as a Blue Rinse, a fairy superweapon similar to a bio-bomb.
Anachronism Stew: In The Time Paradox, Artemis goes back to two years before the first book (which was published in 2001, and uses human technology from that time). Yet, the young Artemis has a mobile phone that can be used to surf on the Internet, be connected to a beamer, has a blacklight to test money and an X-ray scanner. He uses his laptop to send a video message to every Extinctionist's phone, and all of them can watch it. Also, Kronski pays Artemis in bills of 500€, while the euro hadn't come into use (as a physical currency) until a few years later.
Ancient Astronauts: The reason Artemis translates the fairy language so easily is that it is similar to Ancient Egyptian and Artemis theorizes this is because the Egyptians borrowed it from the fairies.
Grub Kelp to his superior officer Trouble. Corporal Grub has a bad habit of forgetting that Trouble is "Captain" while they're on duty; even when he remembers, he seems to think that "Mummy says" trumps rank. At his best he needs cajoling; at his worst he gives the impression that "Mummy says" is the reason such an utter liability is even allowed in the LEP, let alone on the squad of a Captain in good standing like his brother.
Artistic License - Physics: Book 2: Why does Artemis have to swim through the plasma powering the security systems, unless it's really dense. As well as how it can be radioactive in the first place.
From the same book, the Softnose laser rifle is described as a mining tool re-purposed as a weapon. It can be powered by an AA battery, with enough energy for 6 shots. It is also equipped with a suppressor that slows down the laser beam so that it can bore into the target instead of simply vaporising the surface.
There's something in every book really. The infamous Biobomb is described as firing blue light that only kills living beings, while leaving material unaffected. Even if we assume it's not really the visible light that is the damaging agent, in Opal Deception Holly uses her helmet to shield the bomb, and when it proves insufficient she engages her wings and races against the rays! And succeeds! She'd have to be going FTL to manage this.
This continues into Book 8 and is a factor in Artemis's heroic sacrifice.
Author Appeal: The narrative would often go into the horrific outcomes of pollution and how Humans Are the Real Monsters for all their environmentally destructive ways. Also for killing animals for consumption and espousing the virtues of the green and vegetarian lifestyle of the fairies. On a lighter note, he also enjoys going into descriptions of the various high-tech gadgets that appear.
From the last book, Butler: "I am Butler. Everything I say sounds tough. Now, get out of the lake, fairy."
Badass in Distress: In the first book, when Holly gets kidnapped by Artemis she uses a cot to smash through concrete, plants an acorn she snuck in, uses a loophole in an eye-to-eye command to go around the house, neutralizes Juliet with the mesmer, and punches Artemis. And just when you think things can't get worse for the kidnappers, a troll comes in . . .
In the first book, where Artemis is trying to kidnap a fairy. He knows they have to go to a specific place at a specific time to do a specific thing, but if no one shows up (a very likely outcome) then he just sits in a tent all night. It's mentioned that this is exactly what happens for four months.
Also first book: Cudgeon sends in the troll banking on the humans calling for help before it kills them, thus inviting the LEP inside.
Also first book: Artemis' entire plan revolves around 1. the fairies using a time stop, and 2. the fairies noticing a flaw in his orders which would allow them into the manor once he was dead.
Second book: Foaly gets Cudgeon to admit to his Evil Plan on tape because he knows his mark will want to brag about it.
Used by Artemis twice more against Opal in The Opal Deception and The Last Guardian. The latter example is especially notable as Artemis essentially gets Opal to push the 'off button' on her doomsday spell by predicting her rampant narcissism.
Bilingual Bonus: There is a dwarf named Gotter Dammerung. Götterdämmerung is a German word which has been adopted into English to refer to something with a disastrous conclusion. Can also be a case of Punny Name.
Book Ends: The final lines of The Last Guardian are Holly reciting the opening to the first book verbatim.
And a few lines before that, we get a Call Back to Artemis and Holly's first encounter.
The first book is about the fairies sieging a human-held Fowl Manor and the last is about the main group sieging a fairy-held Fowl Manor.
Brains and Brawn Artemis and Butler, each extremely gifted in his area. Myles and Beckett in book 8, the first being a genius toddler on his way to follow the steps of his brother, the second exceptionally strong and agile, but with an intelligence average for his age.
Briar Patching: When Spiro orders Pex and Chips to kill Mulch, Mulch goads them into burying him alive... which doesn't bother him in the slightest, since he's a naturally subterranean fairy.
Camera Spoofing: In The Eternity Code, Foaly spawns holographs to make it seem like all the guards were knocked out from sleeping gas, and Artemis is there against his will. There were only two guards, and the holographs and Artemis don't show up on the camera. At all.
Canis Latinicus: The American editions turn the Fowl family motto into this.
Can't Take Anything With You: In order to simplify things in the timestream, No1 insists that Holly and Artemis strip before he sends them back in time, much to their chagrin. They bargain him down to just underwear. It's a little bit embarrassing for them.
Captain Obvious: Demons have lived in a different dimension from ours for thousands of years, only learning of human customs and culture through one trashy romance novel, which they take as a sort of Bible. No1, a young demon/warlock we first meet in The Last Colony, was particularly interested in the human world, so when he finally gets transported there, he takes great pleasure in pointing out the meaning of human expressions, despite the fact that every other character around him (and the readers) know very well what they mean.
This is somewhat justified at one point as it's pointed out that No1 does this as a way of coping with stress.
Subverted in book six: "I think we all know what D'Arvit means."
Artemis also has his moments: "My butler could kill you a hundred ways without the use of his weapons. Although I'm sure one would be quite sufficient."
Character Development: As the series progresses, Artemis develops from a ruthless criminal mastermind into something almost heroic. A major part of The Time Paradox is contrasting Artemis pre- and post-development.
Particularly obvious from the epilogue of the first book, which states That Artemis healing his mother was nothing but Pragmatic Villainy to stop social services interfering in his schemes, that he would continue to exploit the fairies and be a thorn in their side for years after the Fowl Manor incident, and that Holly would become one of his greatest foes. Though the book itself says that the report is "94% factually accurate, 6% unavoidable extrapolation."
And in The Last Guardian, the Opal clone could count as this or Chekhov's Gunman - she is technically alive after all.
From the same book, we have the eye that Artemis and Holly traded in Book Five. It ultimately leads to his (temporary) death due to a special spell designed to kill any fairies within its bounds. While Artemis is mostly human, the eye is just enough fairy to qualify him.
Turnball Root, appeared in a short story and reappeared in the Atlantis Complex.
That sprite who told Turnball how to re-acquire some magic? That's the first supernatural being who ever appeared on-screen: the fairy who loaned Artemis a copy of her Book way at the beginning of the series. Given that she hadn't appeared since the first chapter of the first book, and this was the seventh, this probably is also a Brick Joke.
It's also to clean up Fridge Logic, because fairies are shown to lose their magic in certain situations, which this sprite may have been in, yet she retained enough magic power to heal some few human maladies.
In Book 4, Opal has herself cloned and leaves the clone in the Argon clinic during a jailbreak so no-one will suspect she has gone missing. In Book 8 she gets her hands on a magical superweapon which becomes magically encoded to only respond to her DNA... guess who Artemis enlists to disarm the weapon?
The Chessmaster: Artemis (literally- one of his disguises as a chess prodigy ended up with a maneuver named after it), Opal Koboi. Spiro tries this, and is pwned.
Children Are Innocent It is stated that Artemis succeeds at finding the People because, being a kid, he is innocent enough to still believe in things like fairies and magic. His actions makes this innocence arguable at best.
Doodah Day. At the end of Lost Colony, he is mentioned as having started working as a private detective along with Mulch Diggums. The Time Paradox takes place mostly in the past, so it's understandable that he wouldn't appear, but Mulch is actively involved in The Atlantis Complex and not only does he not seem to be working as a detective, there is absolutely no mention of what Doodah is doing.
By the time of The Last Guardian, Mulch is apparently a wanted criminal once again with no mention of Doodah.
Minerva Paradizo. At the end of book 5, she is stated to have spent 3 years obsessing over Artemis, waiting for him to return, and she was set up as a very obvious Love Interest. Two books later, and she hasn't been mentioned once since then.
Word Of Godsays she's dating a skier in the Alpes Maritime and has moved on past Artemis.
City of Weirdos: It's mentioned several times that faeries often go to Disney Land on vacation, to no reaction from the human visitors.
Cleaning Up Romantic Loose Ends: A subtler case than most, considering these are childrens books, but in the The Last Guardian we've got Foaly and Callabine happily married and kicking arse, Trouble and Lilli Frond hooking up and a moment between Holly and Artemis at the end, but that could be more of a Friendship Moment.
At the end of book 7, Artemis still has the Atlantis Complex.
Subverted, as Artemis is completely cured at the beginning of The Last Guardian.
At the end of The Time Paradox, Opal from the past is still on the loose in the present.
Clip Its Wings: Chix Verbil is hit in the wing with a softnose laser during the events of Arctic Incident. Holly is able to save his life with some quick thinking and faerie magic, but since the blow ruptured several major arteries, she reckons that he'll never fly again.
Cold Flames: Damon Kronski, leader of the Extinctionists, has a pit lined with flamethrowers which he uses to stage the execution of endangered species for the amusement of his supporters. Unbeknownst to him, another character (who wants the endangered animals saved for selfish reasons) fitted a trapdoor in the base of the pit and replaced the flamethrowers with hologram generators.
Concealing Canvas: Lampshaded by Mulch in the first book. Turns out to be a subversion, as the safe behind the painting is a decoy. Subverted again when the safe is in the painting itself.
Continuity Nod: In the middle of a situation so ridiculous Artemis thinks it might be a delusion in The Last Guardian, he shouts out "Four!" to check he isn't mad again.
Creepy Child: Artemis, especially in the first book. And the third, to the waitress. And again in the sixth.
"Who would want to kill Artemis? Every waitress and tailor on the continent, for a start."
Critical Psychoanalysis Failure: Artemis tends to have this effect on psychiatrists because he is much more intelligent than most psychiatrists and has read up on all the latest approaches to psychology. He can get them to diagnose him with whatever he wants. It helps that he's actually written some of the books his psychiatrists use to diagnose him.
Cultural Posturing: Various fairy characters are fond of reminding Artemis how advanced fairy technology is compared to the "Mudman" equivalent. Unless it's technology that Artemis himself developed after meeting the fairies and reverse-engineering their gadgets. He even impressed Foaly by packing his 3D projection kit, which doubles as a user interface, into a briefcase.
The US edition of The Time Paradox, has proudly Irish Artemis start referring to his mother as 'Mom' after making an emotional breakthrough. She gains the title 'Mum' in the UK edition, but even that may be a version of this trope, as she's referred to indirectly as the very Irish "Mam" in the first book.
The second book, Artemis Fowl and The Arctic Incident, had a line in which Artemis predicts he will be attracted to Holly when he reaches puberty that was removed from US editions. They needn't have bothered, since he was right, and you couldn't have hidden it in TTP without rewriting half the book.
Cut Lex Luthor a Check: Artemis is such a mega genius that he could easily make many millions of dollars as an inventor — and, in fact, he does. The Arctic Incident says that he holds several patents and is designing a Dublin opera house. He does crime in order to make billions. And, you know, for the challenge. He also writes romance novels for pocket change - because he figured out the formula for writing the perfect romance novel, naturally.
Da Chief: Julius Root. Then he gets gibbed. Ark Sool takes the position afterwards, but after he reveals his true nature, he's replaced by Trouble Kelp.
Butler: Focus, Artemis, one dastardly crime at the time. Artemis Fowl: Dastardly, Butler? Dastardly? Honestly, we are not cartoon characters. I do not have a villainous laugh or an eyepatch.
Dead Guy Junior: Sort of: A curious case in Jayjay the lemur (short for "Julius junior") is indirectly named after Commander Root, who isn't dead the moment they choose the name, but is in the future that Artemis and Holly come from.
Deadpan Snarker: so many. Artemis, Foaly, Holly, and Mulch (and occasionally Juliet) enjoy trading sarcastic statements. Mulch lampshades it in the narration of the fifth book:
Their little band of adventurers needed another smart-ass like they needed ten years of bad luck.
Holly: What on earth were you doing, Mulch? The computer says you came all the way down here in first gear. Mulch: There are gears?
Mulch's driving technique is described earlier in the book as being "focus on the wheel and the pedals, and ignore everything else." He also assumed the shuttle had an automatic transmission.
And in The Eternity Code, he scoffs at Juliet when she points out to him that he can't reach the brakes.
And as of The Lost Colony Doodah Day:
Mulch: This close! We came this close to being incinerated. Give me your gun Holly, I'm going to shoot him.
Easter Egg: The "gnommish" coded messages running along the pages of some of the books and hidden in certain cover designs. They're a bit weird. They claim you're a long-lost fairy police officer, for one...
Embarrassing First Name: In The Lost Colony Abbot, the Big Bad of the demons, was named after a character from a book taken from the human world, as were all demons when they come of age. His true demon name is N'zall, which means "little horn" in the demon language.
In the first book, Cudgeon isn't pleased by his foul-mouthed subordinates.
Everyone Owns A Mac: Take a drink for every Apple reference in the books. Good examples are Artemis's iBook, and the line in The Time Paradox about Foaly sucking information from the Apple Mac.
Evil Albino: Kronski seems to be this. He is described as having nearly transparent white skin and purple eyes. Since some forms of albinism manifest with purple eyes, and Eoin Colfer is not known for giving his humans odd eye colors, it suggests he may be albino.
Evil Genius: One per book, two in book six. Artemis in book 1, Opal Koboi in book 2, Jon Spiro in book 3, Opal Koboi again in book 4, Minerva in book 5, Young Artemis and Opal Koboi AGAIN in book 6, Turnball Root in book 7, Opal Koboi AGAIN AGAIN in book 8.
Evil Plan: Each book really. The first one is staged by Artemis himself when he was a Villain Protagonist. "Capture a fairy and ransom them." Simple enough, right? Except he had to find one first, get their book, translate it, and then find a fairy that was worth ransoming.
Exotic Entree: The Extinctionists from Artemis Fowl and the Time Paradox enjoy rendering endangered species extinct... and that, of course, includes dining on highly endangered or outright extinct species.
Expecting Someone Taller: Invoked in Book eight. A dwarf realises that he's only seconds away from being murdered by Opal, so he decides to go out with flair by making his last words an insult. "I always thought you'd be taller. Plus your hips are wobbly."
Extended Disarming: Well, not disarming, but near the start of Book 1, Artemis lists all of Butler's weapons hidden on his person.
Artemis: Let me fill you in on the weapons status. I am unarmed. But Butler here, my ... ah ... butler, has a Sig Sauer in his shoulder holster, two shrike throwing knives in his boots, a derringer two-shot up his sleeve, garrotte wire in his watch, and three stun grenades concealed in various pockets. Anything else, Butler? Butler: The cosh, sir. Artemis: Oh, yes. A good old ball-bearing cosh stuffed down his shirt.
He then goes on to say that Butler could kill someone in a hundred different ways without his weapons.
Eye Scream: The iris cam. Pure genius, but it sparks when changing the settings.
The Fair Folk: "The People" Arrogant, and annoyed with the Mud People, yes.
Fairy Companion: Played with: Artemis facetiously refers to Holly as "my fairy friend" at one point, but she is far too Badass to fit the trope.
Fake Memories: Foaly explains that the mind will naturally create false memories to fill the gaps left by a mind-wipe
Fartillery: Never stand directly behind a dwarf. Trust us on this one.
As of The Atlantis Complex, we see Turnball Root commenting on how the fairies are wasting resources to the point of throwing away something that would have only taken a dab of silicon gel to fix. The fact that it's also a mastercomputer of a space probe makes this an example of bad security as well.
Fanservice: Both graphic novels released so far have found an excuse to put Holly in a somewhat... revealinglight. The scenes in question were both in the original books, though.
Find the Cure: The Time Paradox: the only cure for Angeline Fowl's disease is the brain fluid of the silky sifaka lemur - The catch? Silky sifakas went extinct eight years ago. Artemis himself made sure of that.
Finger in a Barrel: A variation in the first book. Mulch is being attacked by a gang of goblins, and their ringleader summons a fireball and then inhales it up his nostrils, with the intention of breathing fire over Mulch. Mulch responds by jamming his thumbs up the goblin's nostrils; he gets his thumbs burned, but the goblin's innards take most of the damage.
Fire-Forged Friends: Various characters find themselves growing closer through all their adventures and misadventures.
Artemis and Holly are the prime example, seeing as how they've gradually gone from enemies to allies by necessity to somewhat-trusted companions to actual friends to closer friends.
Artemis and Butler, at first, were just 'the closest thing' each had to a friend. By the end of book 2 and all that had happened, Artemis realized that he truly respected Butler. And by book 3, Artemis was willing to go through a great ordeal to save his life.
Holly and Mulch, of all people, became close enough for him to join her as her partner when she quit the LEP and became a private detective.
First Time Feeling: In The Time Paradox, Holly restores Damon Kronski's sense of smell in a particularly fowl smelling Souk, which reduces him to writhing on the floor, clawing at his nose.
Artemis realising for the first time during the Opal Deception that yes, he has friends.
Five-Token Band: Turnball's gang is the Fairy equivalent: One elf, one sprite, one dwarf, one gnome, one goblin.
Forgot About the Mind Reader: Opal Koboi has her none-too-bright henchmen convinced to the point of paranoia that she can read minds, simply by turning on them at random and shrieking "I heard that!" One henchman tests her by thinking treasonous thoughts at her as loudly as possible.
Henchman (thinking): Holly Short is prettier than you. Opal Koboi: Don't stare at me like that, it's bad for my skin.
Four Is Death: Invoked in the entire run of The Atlantis Complex. Caused by the titular magical malady.
Friendship Moment: Many across the series from Holly and Artemis especially, but the ones that stand out are Artemis giving Holly the chance to say goodbye to Commander Root and in the last book, Artemis realizing that yes, he would go to the ends of the Earth (and below it) for Holly.
The first book starts simple enough, Fowl faction vs LEP recon in a hostage situation. Then Mulch has his own agenda, Cudgeon has his own agenda, Holly's agenda shifts away from Root's agenda, and then there's a troll.
In The Time Paradox, Artemis versus Opal. One particular example: When he takes off in the Cessna, it looks as though they are all trying to make a break for it... but then Opal uses her thermal imager to see there is only one passenger. She guesses it is a decoy... but then notices Artemis is concealing the lemur's body heat under his shirt. That's what he wanted her to see.
Gameplay and Story Segregation: An odd example; the faerie language is apparently a language of symbols, but for all the codes at the bottom of the book, each symbol is translated directly to an English letter.
Gasshole: Mulch Diggums, and the dwarves in general.
Gender-Blender Name: The title character (sort of; "Artemis" as a human name is genderless). He also claims to write romance novels under the name Violet Tsirblou in an inversion of Moustache de Plume.
Genius Bruiser: Butler may not quite equal his employer in heist-planning, but he's still pretty damn smart and outstrips him in several other fields.
Genre-Busting: An international espionage/science-fiction/crime thriller with a teen protagonist. And fairies.
Gentleman Thief: Artemis executes elaborate heists for the challenge and, after book one, seems to pick targets that he feels deserve it.
In the sixth book, while it did fit the language-obsessed character, a particular quote seemed to be directed as much at the readers as at the other characters:
"I think we all know what D'Arvit means," said Nol, "But hurkk is not English."
Artemis totally just flipped off Abbot.
Artemis Fowl grinned right back at him and pointed his index finger at the sky. Actually, it was his middle finger, due to the time tunnel switch.
Giant Squid: Artemis is attacked by one in The Atlantis Complex
I'm the nut!explanation Artemis is in a specially-armored deep-sea diving suit, tracking down a giant squid. Unfortunately, he underestimates the squid's intelligence when he realizes the squid is tracking him. He sees the squid pick up a large chunk of a sunken ship in a tentacle and notes that it's like it's wielding a hammer or mallet of some sort. Artemis thinks to himself "Okay, it's got a hammer, what sort of nut does it need to crack?" Cue Oh, Crap reaction when Artemis realizes he's the nut.
A Glass in the Hand: When Artemis enrages Gobdaw in Last Guardian, Gobdaw responds by snapping a martini glass and trying to attack Artemis with the sharp end of the stem.
Green Aesop: The series teems with these, some more subtle than others. As of book five, environmental issues have not featured in the main plot, but the fairy people are quick to criticize humanity's lack of respect for nature and Artemis tends to agree with them in an Even Evil Has Standards sort of way. Book six, The Time Paradox, brings this front and center with the main plot focusing on an endangered lemur. Even the Easter Egg codes in some of the books are somewhat Anviliciously pro-green.
There were less objectionable ways to get oil by-products, thought Artemis.
The seventh book opens with Artemis unveiling his plan to end global warming.
Comes to a head at the eighth book with practically all modern technology being destroyed ('cause of Opal, by proxy) and green technologies replacing them.
Grey and Gray Morality: In the first book, an argument could easily be made for either side being the "good guys".
In the case of Artemis himself, well... on one hand, he is an unashamedly greedy criminal (which his future self readily admits). On the other, he does have some standards, feels some guilt over his plan, and given the set of values that his father gave him, he certainly doesn't think he's doing the "wrong" thing so much as following a twisted sort of "God-helps-those-who-help-themselves" mentality. Plus, two of his less explicit reasons for his kidnapping plot were to heal his mother and raise more money to try and find his father.
In the case of the LEP, some of them did some very questionable things, such as sending a troll into a house where it would be a danger to everyone, including the hostage. Many of them, including characters who were opposed to the troll idea, were later willing to kill several innocent bystanders (Fowl's mother and Juliet along with all of the wildlife) to take out Fowl and ensure that he wouldn't exploit the fairy world in the future. (Recovering the ransom was just a bonus.)
Grudging Thank You: Artemis to Holly at the end of book 2 and Butler to Holly in the first book.
Healing Hands: Any creature with magic can do it, though skill is a factor.
Heel-Face Turn: Artemis, sort of. His father too, after he's recovered, thanks to Holly's meddling.
Strong-minded individuals can put up some resistance to fairy mesmer.
This is also the main reason Artemis's atoms don't get randomly scattered through the time stream due to his multiple travels through it—"willpower," or at least intense focus and preservation of self, was stated to save him.
Hey, You!: It marks a turning point in their relationship when Holly finally calls Artemis by his first name instead of "Fowl" (or "Mudboy"), and (much later) calling him "Arty". Likewise, when Artemis first calls his mother "Mum" instead of the more formal "Mother."
Hijacked by Ganon: In Artemis Fowl and The Time Paradox, the apparent villain-of-the-day (or yesterday) Damon Kronski turns out to be the pawn of Opal Koboi.
Hollywood Chameleon: Discussed. When Artemis learns that Foaly named his Cham-foil invention in honor of the chameleon's signature color-changing ability, he wonders whether or not Foaly is aware that chameleons choose their color based on mood rather than as a means of camouflage.
Hope Spot: A crushing one near the end of The Last Guardian, when Artemis tries to escape the Berserker Gate before it activates and kills him. He manages to jump out of the crater and begins to pass through the magical barrier. Holly is holding his hand, pulling him through, and Artemis thinks that a new life is ahead of him as an ambassador between humans and the People. And then the Gate kicks in and Artemis is dragged back in the crater. Butler doesn't make it to pull him out. Of course, it was only a Disney Death, but still...
Horse of a Different Color: Book eight mentions that fairies once used trolls as steeds in times of war. Mulch figures out the secret and rides a troll into battle against the berserkers.
Humans Are Warriors: During The Opal Deception, a kidnapped Holly and Artemis are taken to an abandoned theme park. Artemis sees some mannequins in a gift-shop window that are dressed up as humans, in various warlike poses.
I'll Kill You!: Loafers in Artemis Fowl and the Eternity Code, after he finally has enough of Mulch's taunting:
Loafers: I'LL KILL YOU! YOU'LL BE MY NEXT TATTOO! YOU'LL BE MY NEXT TATTOO!
Immortal Procreation Clause: Although not immortal, fairies can only have one child every twenty years; humanity's faster reproduction is actually the main reason it was able to more-or-less take the world from them.
Invisibility Cloak: Foaly creates an invention called Cam Foil to make the wearer of it invisible. It's more technological than Harry Potter cloaks, which serves some problems, such as it shorts out in rain and is not invisible to a camera. Also, the circuitry can be easily crushed and the wearer appears as a slight haze, so is still noticeable.
Ironic Echo Cut: From The Opal Deception - "No one could pretend to be in a coma for over a year. Surely not. A fairy would have to be totally obsessed. ... ... Chapter 1: Totally Obsessed"
Is The Answer To This Question "Yes"?: At one point in the first book, they're watching a tape and Root asks Foaly if he can zoom in on Artemis' face. Foaly responds, "Can a dwarf steal the web from under a spider?" Root replies "yes", and Foaly says that it was a rhetorical question.
Laser-Guided Amnesia: Fairy technology can do this, but it's costly and labour-intensive. Used on a random Mafia goon and Artemis after The Eternity Code.
Last of His Kind: Jayjay, the silky sifaka lemur. Not for long, because Foaly is going to clone more.
Legacy of Service: The Butlers have been serving the Fowls for so long that they were the origin of the word butler. The earliest known interaction between the two was the Third Crusade.
Left the Background Music On: In TLC, where Minerva is being held captive, she thinks that the situation is as tense as possible, and there's even theme music playing. Then she realizes the music is actually the Big Bad's cell phone ringing.
Leprechaun: Actually LEPrecon: the Lower Elements Police reconnaissance unit. The stereotypical human view of Leprechauns is a source of significant embarrassment for the elves. And Recon are actually the source of that stereotype, if the multiple references to "the top hat and shillelagh days" in the first book are anything to go by.
Loophole Abuse: In one of Holly's combat simulation exams, she beat an insurmountable number of enemies by shooting the projector. As they didn't have any rules against that, they had to let her pass.
Also the way she passed her LEPrecon exam. Despite the exam being interrupted by his brother Turnball and Holly saving his life, Julius Root says Holly failed because she didn't follow his orders. Then Holly shoots him with her paintball gun, because Root said the one sure way to pass was shooting him before he could shoot her (which nobody had managed in a century).
Lucky Translation: Trouble Kelp is called Truba in official Russian translation. It does sound similar as far as translation goes, and even though its main meaning is "pipe", its second meaning is "a disastrous situation"
Luxury Prison Suite: Turnball Root manages to get one of these, receiving each item as a reward for selling out his former comrades
Magic Knight: Demons in Artemis Fowl and The Lost Colony are divided into two castes: ordinary demons develop no magical power, but metamorphosise into monstrous forms when they come of age, while warlocks develop magical talent instead of muscle. Demon warlord Leon Abbott managed to steal some magical power from a warlock when he interrupted a spellcasting ritual and caused a freak accident, and uses the stolen magic to secretly bewitch the rest of demonkind into serving him.
Mega Corp.: Koboi Industries, prior to Opal's incarceration, had many legitimate enterprises that manufactured "everything from weapon parts to medical equipment" and even ran illegal front companies that sold obsolete fairy technology to humans. This allows Opal to cripple both human and fairy technology when she murders her past self and causes the majority of Koboi technology to violently annihilate itself.
Myopic Architecture: Butler destroys an ancient stone doorway because it's much weaker than the modern armored door. Also Mulch Diggums gets through the floor of an otherwise secure area.
My Species Doth Protest Too Much: Nº1 is intellectual and gentle at heart, but all the other demons he grew up with were "hit first, question later" Blood Knights overflowing with machismo. After years of trying to fit in, this (and some hypnotic prodding) lead him to leave the island. Turns out, though, that he's not like the rest because he's the first warlock to appear in ages, and warlocks just don't have the same bloodlust that most demons do.
Narrator All Along: Holly Short is revealed to be the narrator of the series at the end of The Last Guardian:
Holly: "It all began in Ho Chi Minh City one summer."
Never a Self-Made Woman: Juliet grows up wanting nothing more than to duplicate her brother's accomplishments as a bodyguard and live up to the family name. Book 3 has her coming to terms with this attitude. Unfortunately for Juliet fans, her refusal of the bodyguard profession and conscious attempt to level in Badass means joining a lucha libre troupe in Mexico and disappearing for the next three books. This is subverted with Opal Koboi because even though her father was successful and she entered the technology field too, he never encouraged or helped her in any way and basically wanted her to stay in the kitchen. Also, her company eventually puts his company out of business.
Averted with Holly. She's actually the first female LEP Recon officer, and this is a large part of book 1.
New Powers as the Plot Demands: Dwarves. Seriously, at least one new one per book, kinda like Silver AgeSuperman. Along the course of the series, we learn that they can: tunnel by eating through earth, fire a devastating barrage of digested rocks/mud/whatever they just dug through, propel themselves underwater and ignore the bends because of intestinal bacteria, have saliva that works as a healing balm, can cling to walls if dehydrated, have glow-in-the-dark spit, which can also solidify to trap enemies AND contains a sedative capable of knocking people out (how exactly is only explained as far as Mulch's comment that "You didn't fall asleep because I didn't do your head"), have prehensile beards/antennae (very handy lockpicks/emergency automatic surgical needles)....
Lampshaded. "Even the dwarves don't know most of their abilities,"
In The Last Guardian, the present day Opal is able to detect the existence of the past Opal existing simultaneously in her head.
No Eye in Magic: The fairy 'Mesmer' ability, which - with direct eye-contact - allows the fairy to hypnotize and control a person. Reflective lenses such as shades will block it (and, on one memorable occasion, mirror-surfaced contact-lenses are used to covertly block a Mesmer), but it CAN be conveyed across video-link, albeit at a significant power-loss. (Strong-willed people can shrug off Mesmer if it's by video. With direct eye-contact, the best you can hope for is to resist violently enough to die rather than carry out the commands of your fairy master).
Non-Action Guy: Artemis is brains, not brawn, and frequently regrets his lack of physical fitness and coordination when he is forced to take an active role in things. Foaly is more successful in avoiding the action; his involvement rarely requires him to leave his computers.
Obstacle Exposition: Happens in every book, sometimes more than once. All that advanced fairy tech seems designed to create Mission: Impossible security system scenarios.
Oddly Small Organisation: Artemis' criminal empire pretty much consists entirely of himself and Butler. After his father's disappearance, Artemis apparently scaled back the family operations to only one's which he could oversee personally (almost entirely grand larceny and fraud), and heavily invests the profits from these (although he does make great use from his family's and Butler's vast network of contacts).
In Book 1, Commander Root is nearly killed by Artemis with a remote bomb. Commander Root, being a fairy, has to use his training to recognize the symbols... numbers... getting smaller... a countdown!
In Book 4, The Opal Deception, Holly, after seeing a bio-bomb detonate in Artemis's hotel room, has to try and stop another one from detonating and killing her, as Artemis got out safely. She covers it with her LEP helmet, but the helmet crashes away and she has to outrun the deadly blue light.
All over the place, most notably in The Last Guardian with the pirate duo Salton Finnacre and J'Heez Nunyan and the Chinese Warrior Yezwi Khan.
The dwarf engineer in The Last Guardian is named Kolin Ozkopy.
Artemis himself is fond of using these as pseudonyms. He published some romance novels under the name Violet Tsirblou ("violets are blue...") and submitted articles to psychology journals under the names "C. Niall DeMencha" and "Sir E. Brum". Also, the way Artemis makes a point of mentioning when he used a pseudonym can be seen as Lampshade Hanging.
Put on a Bus: Juliet joined a wrestling team, and Minerva wasn't even mentioned in Time Paradox.
Race Lift: Holly Short and elves in general are described as brown-skinned and, except for the pointy ears, able to pass as short humans in the books, but the graphic novels give her skin as fair as Artemis's. More subtly, the Butler siblings are described as noticeably part-Asian in the books, Butler passing easily for Chinese at one point despite being blue-eyed and terrifyingly tall. It's not noticeable in the graphic novels at all, to the point Juliet looks like a palette swap of Angeline.
Real Men Wear Pink: Butler is a Le Cordon Bleu chef and enjoys old romance movies (his favourite is "Some Like It Hot"; tell anyone and he'll hunt you down); Artemis writes poetry and classical music, enjoys opera, theatre, and has designed an opera house.
Reed Richards Is Useless: As part of the long-running environmentalism anvils the Fairies never provide (willingly or unwillingly) technology that would help prevent humanity from polluting.
Re Lex: The fairy language appears to be a Re Lex of English with Irish influences.
Replacement Flat Character: Artemis becomes a more decent person as the books go on, so The Lost Colony adds Minerva Paradiso who's doing nearly the same thing as Artemis in the first book. The younger Artemis they meet while travelling back in time in The Time Paradox also counts.
Retcon: A minor one involving the story of how Foaly met his wife Caballine. In The Lost Colony, the two met because Caballine was a fan of one of Foaly's inventions. In The Last Guardian, the two met because Caballine was mistaken for a bank robber by Foaly's software and was thrown in jail, with Foaly having to apologize in person.
Retroactive Preparation: In The Time Paradox Artemis and Holly are locked in the trunk of a car and decide that later on they'll go back in time and ask Mulch Diggums to come rescue them. Soon after, Mulch breaks open the trunk. They try something similar later on in the book, but realize that it only works once.
Rewarded as a Traitor Deserves: Happnes to Mulch in Book one. He tries to sweet-talk some goblins by claiming to sympathise with them, only to find out that the only thing they hate more than a dwarf is a traitor to his own kind.
Ridiculously Difficult Route: In The Arctic Incident, Artemis and his friends are trying to find a way inside Koboi Labs. The good news is, Mulch has a cousin who worked as a contractor during the labs' construction, and they discovered an underground fissure that leads straight to the labs' foundations. The bad news is, the fissure opens and shuts periodically as it expands and contracts with heat from the Earth's core, it will only be wide enough for their shuttle to navigate safely for three minutes at a time, and it's at it's widest for a few moments right before the next magma flare.
Sadistic Choice: The beginning of The Opal Deception Opal forces Holly to choose between saving Commander Root and Artemis, then compounds the sadism by offering her a false third option. To add even more insult to injury, Opal didn't give Holly enough time to save Artemis even if Holly had left immediately.
Science Is Wrong: Subverted. Human understanding of certain scientific concepts is wrong, but only because human observations are limited by the fact that magic is actively hidden from "Mudmen." The scientific method is still a-okay.
Ship Tease: Holly kissing Artemis in Book 6 and more.
Artemis hugs Holly to activate a weight-sensitive panel to open a locked door.
They have to undress down to underwear and then hold hands in order to Time Travel. N°1 makes a parting shot about pronouncing them "man and elf". Then, when they arrive in the past, Artemis is aged and Holly rejuvenated to the point where their age disparity disappears. For bonus points, thinking about this disturbs Holly. That almost crosses the line from Ship Tease to Unresolved Sexual Tension.
For the non-Artolly shippers, Book 7 reveals that Holly and Trouble Kelp went on at least one date.
Also in Book 7, Orion. While he usually spends time pointing out how much he loves Holly, he also lets it slip early on that Artemis also has similar feelings, but chooses to hide them.
Book five covers the time period in which Artemis experiences puberty. Being Artemis, the enormous mass of new-found emotions and hormones is little more than an annoyance, but, also, being Artemis, he has no trouble mentioning this annoyance whenever he was distracted by a pretty face. This also just happened to be the book in which Minerva- essentially a slightly younger, Distaff Counterpart to Artemis Fowl- heavily features. Furthermore, he actually mentioned feeling attraction towards her, specifically. And yet, beyond these passing mentions, the matter comes up roughly twice: once when they get along incredibly well on the phone, which lasts about twenty seconds, since they are currently attempting to ruin each other's plans, and again towards the end at Minerva's side when she is revealed to have been thinking about Artemis in an admiring sense.
The Last Guardian has the scene where Artemis and Holly attempt to out maneuver each other to save them from performing a Heroic Sacrifice . Quelle suprise, Artemis wins, but the scene wouldn't be out of place in a romantic drama with more traditional love interests.
He kisses her goodbye, too. And when he comes back to life he and Holly are left in a field of roses. Ahem.
The Slow Path: Inverted in The Lost Colony. They return three years after they left. No. 1 was worried it would have been more.
Played for Laughs in The Last Guardian, where Foaly uses the power of a van whose communication system has his personality to set off a time-stop; what takes five seconds for him is five years for the van.
Foaly's van: I missed you so much, dude! Did we win?
The Smurfette Principle: Deconstructed like whoa in the first book, when Holly point-blank asks Root if he's harder on her because she's a girl. He admits it, and then points out that she's the first female in Recon, and needs to set an example. It's also worth noting that the only other female up for the job Holly considers a 'bimbo'.
Sphere of Destruction: Biobombs. They explode in a (usually) sphere of light and kills everything within range, although they can be contained by Time Stops, which have a pentagonal base.
Spoiler Opening: If you know how to read Gnommish, the first page of The Last Guardian says The Last Will and Testament of Artemis Fowl. This comes up in English in the third act.
Stable Time Loop: More or less. The Time Paradox has so many piled on one another it'll make your head spin. Even just planning to do something when he got back to the future made it retroactive fact, allowing him to reap the benefits before actually doing so. Even more, Artemis's obsession with fairies in the first book is the result of residual memories from his future self, in which he learned about fairies and his own involvement with them, after a Mind Wipe.
Super Cell Reception: Artemis once received a text message in the Arctic. Sent from a laptop inside the Earth. One could speculate that the fairies have set up underground Internet and cell phone service providers... but it was Artemis' own laptop, so it probably ran on a plain old human-run ISP. Then again, it was Gadgeteer Genius Foaly at the keyboard, though Artemis himself notes that it should have been impossible for him to receive the message.
The story adheres more to actual physics when, asked if they can send a reply, Artemis nonchalantly quips, "Certainly. Just give me six months, some specialized equipment and three miles of steel girder." Foaly himself mentions how hard it was to patch into the human networks.
The Last Guardian mentions that all fairy communications halted because the human satellites they were piggybacking on fell from orbit. They probably just install devices to block signals of human origin and use the full capacity of the human tech to their own benefit. Artemis, being Artemis, would have found unblocking the device child's play.
Swiss Bank Account: Artemis Fowl has several, though probably not as many as when he was still (moderately) evil. A couple of villains (most notably in The Eternity Code) also had Swiss Bank Accounts, ripe for Artemis to dig his fingers into.
Take That: Colfer can be utterly ruthless in his description of civilian fairies in the first book.
A particularly noteworthy example is Dr. J. Argon, a pastiche of celebrity doctors as well as psychologists in general. Colfer also makes a rather deliberate note in the first book that Argon is "a psychologist from below the United States".
A short one at politicans in general: "Cudgeon was doing what politicans did best: trying to duck responsibility."
Technology Marches On: A fair amount of Fairy technology and equipment considered superior to the human variety at the start of the series by either the characters or the author have become decidedly less so as the years have gone by. Notable examples include wrist GPS, wafer-thin laptop computers and the iris-cam. Several Future Soldier Programs currently in development will almost certainly make the original LEP Recon jumpsuit the next casualty.
Teen Genius: Artemis, of course. And Minerva, who managed to calculate when and where demons will show up on Earth, without having ever seen the fairy book. Although she did have Queffor(sharing a body with Abbot) to give her the calculations for it.
Teen Superspy: Artemis is one, albeit self-employed. No government agencies for him - Artemis has the style and the gadgets. Juliet is another, and even joins a SWAT team in The Eternity Code.
Translator Microbes: Fairies are able to converse in all languages, including dolphin and dog. This is explained as being partly one of the benefits of fairy magic, and partly because fairies were the first creatures to develop language, and all other languages are at least partly based on Gnommish as a result.
Trope Namer: An in-universe example: we're told Butler's family is so highly regarded, the profession was named after them.
Turn in Your Badge: Root keeps threatening Holly with this, especially after being seen by a toddler.
Ultimate Job Security: Invoked by Foaly. He designed most of his tech so that if anyone but he tried to operate it, a hidden virus would "bring it crashing down around their pointy ears". Needless to say, he abuses this situation by talking down to and making cracks about his superiors, knowing full well that even suspending him would greatly handicap the whole organisation.
Wall Crawl: One of the dwarves’ adaptation is the ability to absorb moisture through their pores, which enlarge when dehydrated. While this is useful if you are trapped in a cave in, Mulch makes use of their suction-cup pores to scale glass buildings.
Wistful Amnesia: Artemis post-mindwipe. Then he shows his former self when he discovers contact lenses he made to cheat the mesmer. As of The Time Paradox, Artemis being interested in fairies in the first book is actually due to this.
With Due Respect: In The Atlantis Complex, Holly tells Foaly that the guidelines which suggest that in her situation she should retreat to a safe distance and construct a bivouac are "with respect... a pile of troll weevils." Foaly, who helped to write those guidelines, asks if she actually knows what respect means.
World of No Grandparents: Mostly. Artemis' grandfather gets a nod in The Atlantis Complex, it's mentioned in the first book that his maternal grandfather died when he was two, and Angelina thinks Artemis is her father-in-law at one point. But that's about it.
Writers Cannot Do Math: In The Time Paradox, Artemis and Holly are sent back eight years in time. But in The Last Guardian, it is mentioned multiple times that past!Opal has been removed from her timelinefive years ago. It seems Eoin Colfer forgot to add the three 'skipped' years from The Lost Colony in TLC.
Xanatos Gambit: In the first book. After abducting Holly, Artemis notices she has a tracer on her wrist so he does some quick soldering and gluing to place a tin camera inside. If it works then great, but if it doesn't, its still off Holly and all he loses is an advantage he never expected to have in the first place.
Xanatos Speed Chess: Not only can Artemis come up with new plans on the fly, he can calculate their probability of success.
Foaly: "Do you realize he had less than a minute to come up with this plan to save Butler's life? That's one smart Mud Boy."
Year Inside, Hour Outside: During The Time Paradox Artemis and Holly spend about three days in the past, whilst for Foaly and No.1 it's ten seconds. This is played for laughs at the end of the book. Doubles as Leaning on the Fourth Wall as the reader leaves Foaly beginning to count to ten, sees the whole of Holly and Artemis's journey and "returns" when he says it was the longest ten seconds of his life.
Bodyguard etiquette demands that Butler never reveals his first name to Artemis to keep their relationship professional. He reveals it in book 3, after he's been shot and believes himself to be dying - it's 'Domovoi', a slavic word meaning 'guardian spirit'.
If Holly calls Commander Root 'Julius', it means she's about to disobey an order or do something else that will annoy him.
In The Opal Deception, Mulch only refers to the Atlantean sea-elf Vishby by his real name once, when he's imploring him to flee a submarine moments before it gets crushed by immense water pressure. The rest of the time he uses the demeaning nickname 'Fishboy'.
Turnball's smile never wavered, and he kept it bright by promising himself that he would dispose of this fool the second he was no longer of any use.
Your Mom: Butler distracts some men in the first book by insulting some men and saying that their mothers must be so proud.
The stranger had crossed a sacred line. He had mentioned the men's mothers. Nothing could get him out of a beating now, not even the fact that he was obviously a simpleton. Albeit a simpleton with good vocabulary.