While spoilers for this page will be marked as usual, the book itself is intended to be read after watching Amphibia. As such, all spoilers from the show will be unmarked here. You Have Been Warned!
Marcy's Journal: A Guide to Amphibia is a spin-off book of Amphibia, co-written by Matt Braly and one of the series' show-writers, Adam Colás. Besides introducing new pieces of information regarding the world of Amphibia that were previously absent in the show proper, the book gives insight into what Marcy was up to while Anne moved into Wartwood as well as her inner thoughts during the second and third season of the series.
This book contains examples of:
- A Birthday, Not a Break: With The Reveal that Marcy's birthday is between January 20 and February 18 and with the second half of season 3 taking place weeks after Christmas, it subtly indicates Marcy spent her 14th birthday being possessed by the Core.
- And Now for Someone Completely Different: Anne takes over as the author of the journal with Marcy being out of commission in the aftermath of "True Colors".
- Arc Villain: Ernst is the primary antagonist of the first part of the journal, though he's ultimately just an Unwitting Pawn to Andrias (and by extension the Core).
- Art Shift: The sketch of Anne and Sasha fighting is drawn in a more Animesque artstyle, with sparkly anime eyes and slightly more realistic proportions.
- Book Burning: The cult Marcy mentioned in her Theme Song Takeover are revealed to be burning historical records and documents. The whole thing was a plot by Andrias, through his patsy Ernst, in order to keep Marcy in the dark about the prophecy.
- Cathartic Crying: Both Marcy and Anne are subject to this trope. During the infamous Flipwart game, Andrias's question about Marcy's friends and family causes her to burst into tears abruptly and confess everything to him. She later notes that she had been "bottling up a lot of heavy stuff" and makes it a point to not do it again. As for Anne, the book explains that she was actually repressing the trauma of everything that happened in Amphibia and the thought that her friends might be dead. She resolves to stay strong so she won't scare her family. However, she eventually reaches her breaking point during the events of "Escape to Amphibia", when she tearfully claims that she's helpless.
- Cerebus Retcon: Marcy's journal gives a darker look as several event in the show.
- Anne didn't actually take Marcy being stabbed by Andrias well, and the possibility that she and Sasha could be dead affected her sleeping and almost had an emotional breakdown if the thought of her friend being dead crossed her mind.
- Marcy had to go through several doctors and be hospitalized after her adventures in Amphibia. It didn't even help that Marcy required a lot of therapy for all the trauma and emotional baggage she bore over the course of the show, from her parental issues and dependence on her friends for emotional support, to being backstabbed—both figuratively and literally—and played by people she once trusted.
- Commonality Connection: Andrias and Marcy at one point bonds over Marcy talking about her woes regarding her strict father, with Andrias telling her that his father was also very strict.
- Conversational Troping: Marcy calls Found Family (referring to the Plantars) her most favorite trope.
- Cult: The cult Marcy mentioned in her Theme Song Takeover is revealed to be called "The Order of the Olm", engaging in Book Burning in Newtopia. As it turns out, they were merely pawns for Ernst, a former Night Guard captain who faked his death, having been paid by Andrias to covertly destroy any reference to the Calamity Gems, the music box, and the prophecy in order to keep Marcy from learning about it until it was too late.
- The Faceless: Subverted. A section of the journal finally reveals what Marcy and Sasha's parents look like.
- Fantastic Caste System: Marcy notes the caste system of Amphibia, describing it as frogs at the bottom as farmers and laborers, the toads as soldiers and enforces of the rules created by the newts, who are legislators and nobility. Marcy never indicates that she has any issue with this. On a more comical note, the Newtopian Night Guard's oath also specifically lists the order of priority of who the Guard should protect as Newts at the top and Frogs at the bottom.
- Innocently Insensitive: Marcy's Fatal Flaw in the show is very apparent in the book. She doesn't have any problem with Amphibia's current Fantastic Caste System, calling it "Fun", and often describes the world and its people with a clear dissonance, seeing it more as a story or game. When her Night Guard compatriots are angry that their old commander betrayed the Guard, Marcy can't fathom why "He probably had a good reason" doesn't make them feel better. She does show care for them and others, helping them track down Ernst to give them closure, but also says that she wants a satisfying resolution to their arcs, again treating a real-life situation with the amount of seriousness she would a fictional story. But as the story goes on, she begins to overcome this flaw.
- Instant Expert: The entry on Marcy beating Andrias at Flipwart revealed that she picked up the basics pretty quickly, and though Andrias gave her a hard time she managed to win with a brilliant gamble.
- I Should Write a Book About This: One of Marcy's entries during the finale's Time Skip reveals that she had made a webcomic based on Anne's adventures in Amphibia, aptly titled "Amphbi-Anne". She even mentions that a studio has recently bought the rights to it, leaving her wondering if her story would be adapted into an animated series.
- Jerkass Realization: In Entry 103, while she admitted it was rude to read the journal's previous entries, Anne realized how ignorant she was to Marcy's pain, even questioning herself if the latter kept everything hidden even from her first friend because she hurt her in some way in the past, so much so that Marcy believed Anne and Sasha wouldn't listen to her. It's implied this is the main reason why she was willing to forgive her in "The Beginning of the End".
- Katanas Are Just Better: Played for Laughs. One of Marcy's sketches depict Anne and Sasha fighting drawn in an Animesque artstyle, complete with Sasha wielding a katana.
- Kicked Upstairs: Andrias promotes Marcy to a royal advisor after she returns from the Dawnblood Islands, clearly to make sure she won't get the chance to go on any more unsanctioned Night Guard missions.
- Late-Arrival Spoiler: Since the book is meant to be read after watching Amphibia, it is rather cavalier about revealing major spoilers from the show. Andrias' true colors are heavily foreshadowed, and Marcy's truth is rather openly talked about, both of which are enormous Wham Lines in the show.
- Meanwhile, Back at the…: The first section of the journal reveals what Marcy was doing in Newtopia during Season 1 while Anne moved in with the Plantars in Wartwood.
- Once More, with Clarity: The book expands on several of the scenes shown in Marcy's Theme Song Takeover, most notably the scene of Marcy and Yunan fighting pirates, who were actually actors taking their
Method Acting too far, and the scene of Marcy fighting a cult which was just a front for Ernst's operations. - Queer Establishing Moment: Terri is referred to with gender-neutral pronouns like they and them, implying them to be nonbinary.
- The Reveal: The journal reveals several facts and plot points that were never mentioned in the show:
- Marcy ended up joining the Night Guard by succeeding at an Unwinnable Training Simulation when no one else had done so before, successfully stealing a golden egg from a Giant Enemy Crab.
- The Cult mentioned in Marcy's Theme Song Takeover was called the "Order of the Olm", engaging in Book Burning in Newtopia. They were really just indirect pawns of Andrias, who had paid a Night Guard captain to fake his death and eliminate any records that could let Marcy uncover the prophecy of the true history of Amphibia before they could reclaim the gems and their powers.
- Anne provides the journal with pictures of Sasha and Marcy's parents, as well as revealing how Sasha's parents divorced when she was really young and are both in new relationships.
- In one of Anne's entries, we learn how Marcy and Anne first met. It was at a beach and Marcy was building a giant sand castle with blueprints and everything, and Anne got caught up in her enthusiasm and helped her defend it against the incoming tide.
- Frobo is a Rogue Drone from the other Frobots because his main programming rules were overridden when he was accidentally constructed in "Fort in the Road".
- The girls' astrology signs reveal that Marcy's birthday is between January 20 and February 18, Sasha's is between March 21 and April 20, and Anne's is between May 21 and June 20, confirming Marcy is the oldest and Anne is the youngest among the girls.
- Valeriana created the Calamity Box as a way to unite the Amphibian kingdoms millenia ago. When this led to the Leviathan family invading and subjugating other worlds, she became overcome with guilt and while her body perished, her spirit remained to seek redemption.
- Sequel Hook: Following the end credits of "The Hardest Thing", Anne, Sasha and Marcy are enjoying a sunset on the pier when Anne receives a phone call from Terri telling them to come to their lab right away as they have some exciting news for them all. The girls meetup at Terri's lab the next day.
- Shout-Out:
- On the way to the First Temple, Marcy mentions her favorite video games: The Ballad of Zorda, a clear parody of The Legend of Zelda.
- One of the plushies seen in the claw machine near the end of the book looks just like Wammawink. Another is clearly Hooty.
- The Stations of the Canon: Once the journal reaches the point where Marcy is introduced on the show, the journal entries mostly go episode by episode until the end.
- Stepford Smiler: Anne's entries on Earth reveal that she really did not take Marcy being stabbed well, and many of the moments where she was seemingly goofing off were her trying to repress and distract herself from her worries.
- Understatement: Andrias and Marcy bond when Andrias tells her that his father was also very strict. Considering what an abusive, manipulative monster Aldrich was (and still is), calling him "strict" is an absurd understatement.
- The Un-Reveal: We never learn exactly how the music box ended up in the thrift store where Marcy found it. Anne even tries going back there for clues to a way back to Amphibia once she returns to Earth, but the owners sold the place and moved.
- Unwinnable Training Simulation: When Marcy is trying out to join the Night Guard, she's tasked with taking a golden egg from a giant crab outside Newtopia. It's only after she succeeds by redirecting steam from a geyser into said crab, forcing it into hibernation and letting her waltz in and take the egg without resistance, does she learn that the test was supposed to be a way to see how she'd deal with an impossible mission and that no one's actually managed to successfully complete it before her.
- Unwitting Pawn: Ernst was anonymously hired by Andrias to destroy any records in Newtopia about the Calamity Gems or the prophecy in order to keep Marcy from finding out about it until it was too late.
- Voodoo Shark: It's mentioned in passing that the official explanation the government gave for Andrias's "Frog-vasion" was that it was a movie shoot that went horribly wrong. This, of course, raises further questions, such as why anyone would believe a movie shoot would be done in a crowded city without any warning.
- Western Zodiac: One entry shows that Anne is a Gemini, Sasha is an Aries, and Marcy is Aquarius.
