Yeah, it's a children's book. And yes, the lizard is a good guy.
"Aurora the Flier, I bond to you...Our life and death are one, we two...Through dark, through flame, through war, though strife...I save you as you save my life."
The bonding ceremony between flier and human
The Underland Chronicles, abbreviated fondly as TUC, was written author Suzanne Collins as her debut series of novels. The books consist of:
Aerith and Bob: Gregor and his sister Boots come down to the Underland, where they meet people with strange names such as Dulcet, Vikus, Solovet, Luxa, etc. and then Gregor finds out that "Here among all these strange names [is] a Henry"
Applied Phlebotinum So...many....prophecies. Not to mention the plot-helping mutations.
Action Girl: Queen Luxa. And Solovet. Okay, pretty much all female characters save Nerissa.
Lampshaded in Book 5, when Gregor realizes that if his rager skills fail him, he's just a twelve-year-old kid who's had a few sword lessons, and therefore in big trouble.
The Berserker: Gregor and Ripred are both "ragers" — a person with highly developed warrior skills, a natural-born killer.
Blessed with Suck: Everyone in this series has some sort of tragic past.
More specifically, Twitchtip the 'scent seer' whose sense of smell is so accurate that she can smell secrets — not a fast track to the popular crowd. Also Gregor as a rager, which means he has to pay special attention whenever he fights so he doesn't kill anyone. Great fun.
Also, Nerissa. Funny how a society built on one man's prophecies treats their own personal prophetess so poorly.
Character Development: Oodles of this. It's quite refreshing, actually. Gregor goes out of his way to point this out in Luxa when she goes to Temp for advice in later books.
Covered with Scars: Ripred. Gregor also racks up an impressive total by the time the last book rolls around.
Dark Is Not Evil: Apparently not. Gregor, the hero, wears black armor during the final battle, and his bond is black as well. Not to mention the Bane is white.
Die Laughing: Some plants in the Jungle get you so high that you don't notice the attacking vines.
Establishing Character Moment: Interestingly enough, the villain gets one after his initial introduction. We first meet the Bane as a baby, whose cries for his mother make it impossible for Gregor to kill him. What could be more innocent? Well, in book 4, we learn he killed his devoted caretaker. Still, he said it was an accident, and he's so big he might not know his own strength .. he tried to ''eat him'' to cover it up? (Though, real rats do often eat their dead to keep predators from smelling them and finding the nest.)
Evil/Heroic Albino: The Bane and the Underland humans, respectively.
The Drag Along: Temp and Boots, mostly. They never really do anything on the quests.
Actually, Temp and Boots did do something in book three. Temp kept on warning them, first suggested the idea that the cradle/cure might not be where they thought it was, and Boots did her dance.
Ripred: And if Temp is right, it would explain one thing .. The point of having a crawler on this whole hellish trip! Honestly, how has he added to anything of significance? No offense, Temp, you've been a real champ about babysitting, but what have you contributed? Nothing! Maybe this is it! Your big moment!
Fandom: A rather small one, considering, but the fanfiction for the series has a few exemplary pieces that rival the original works.
Fantastic Racism: Even though the crawlers/cockroaches, gnawers/rats, spinners/spiders, fliers/bats, etc. that coexist with humans in the Underland are not human, they are sentient and treated as full characters on the same level as humans. Prejudices held among human characters towards these species are even treated as equal to any intra-human bigotry.
Failure Knight: Poor Hamnet. He shouldn't have listened to his mother and let the flood gates open so that everyone would drown. Later we discover that Ripred is this for his dead mate and pups.
Fair Weather Mentor: Ripred could fit into this, particularly in book three.
Game of Nerds: The code-breaking team in book five. They're the Underland version of computer geeks.
Grudging Thank You: People in the Underland are apparently very haughty.
Jerk with a Heart of Gold: Ripred. So much. Emphasis on jerk in book 3, emphasis on heart of gold in book 5.
Book 5 is the shining example. Ripred comes into the code room expecting to see another of Gregor's annoying (to him) siblings. He stops short, sees Lizzie, and gets an expression of tenderness on his face. Not to mention sleeping next to Lizzie after she has another panic attack during the night.
Missing Mom: When Gregor's mom gets the plague in book 3, she spends most of the rest of the series recuperating in the Underland.
Reality Ensues: The ending refused to find any half-baked excuse to let them back into the Underland... HOWEVER, The ending was very, very ambiguous, and there was absolutely no way to tell what would happen next.
Rebellious Princess: Luxa owns this trope completely, but makes it seem pretty cool.
Scars Are Forever: Ripred. Later Gregor as well, which he realizes in part of his Bittersweet Ending.
Shipper on Deck: Very much averted. Howard seems hellbent on making sure Gregor and Luxa never go on a date.
Of course, that could be because he secretly loves Gregor. Fans seem to believe this.
And there's Gregor's mom who secretly approves of Luxa, because she's "got attitude."
Strange Syntax Speaker: The cockroaches from Gregor The Overlander tend to mix up verb and subject placement as well as using repetition of certain sentence elements, such as "Do it, I can, do it," or "be small Human, be?"
Theme Naming: All of the bats have names taken from Greek mythology. Additionally, Luxa's mother is named Judith, while Judith's twin is named Hamnet and their sister is named Susannah. William Shakespeare had a daugher named Susannah and twins named Judith and Hamnet.
War Is Hell: Gregor realizes this is true for both the Underland and Overland in the ending chapter.
Well, Excuse Me, Princess!: Gregor seems to love mocking Luxa's stiff conduct and all that. Has some pretty funny moments.
What The Hell, Townspeople?: The Regalians still scorn Gregor even though he's saved their lives multiple times.
The ending of Book Five has Gregor tell off what amounts to the ENTIRE Underland. The Bane's dead and the humans and rats are ready to live together peacefully. Luxa then announces that the rats are being sent to live in the most hostile region of the Underland. Ripred isn't amused, and both sides are ready to go to war right then and there. Gregor tells all of them off not just for being so stupid after both sides have been devastated, but also for Ripred having come all this way with them and Luxa treating him like dirt.
Wham Line: That encoded message in Gregor and the Code of Claw? It says Twitchtip died in pit. Also, the entirety of Luxa's declaration of war against the gnawers.
You Can't Fight Fate: In book 3, when Gregor's mom refuses to let him or his little sister go on the quest, she falls ill with the plague he needs to help find the cure for. Conspiracy Time! Solovet.
You Can't Go Home Again: Averted, mostly. This happens a bit in the first book, but then Gregor goes on this quest to find his missing dad and all that. Otherwise they want him to go home. And then come back for the next 4.