Marcy Wu is a human girl who serves as a supporting character in Amphibia. She is a 13-year old girl who is friends with Anne Boonchuy and Sasha Waybright. She was the one who discovered the Calamity Box and informed Sasha about it via text message. She was seen next to them when Anne opened the Calamity Box that teleported her, Anne, and Sasha to Amphibia, not knowing that in truth, she heard about the box and decided to use it to escape to another world after her father got a job out-of-state and was forced to move with them, threatening her friendship with Anne and Sasha, hoping that Amphibia would be her escape from reality. She also attended Saint James Middle School. When she had arrived in Amphibia, she was warped inside the walls of Newtopia and after doing some work for the newts, she became the Chief Ranger of the Newtopian Knight Guard, who under her title "Master Marcy" works directly for the king of Amphibia, King Andrias. But as of the Season 2 Finale, she was forced to confess she was responsible for sending them to Amphibia, and was critically injured saving Anne and the Plantars from King Andrias, was put in a rejuvenation tank, and is now possessed by The Core. She is an intellectually-gifted person, but she has an extreme case of clumsiness, as she ends up nearly running into dangerous situations in her obliviousness. Regardless, she has enough strengths to pull through challenges even alone. She is played by Haley Tju (Sqweep, Karmi of Big Hero 6: The Series, and Nu Hai).
Marcy is revealed to have been an oblivious clumsy person, and yet has an A+ record with knowledge in science. She also enjoys larping and fantasy escapism, and yet Anne and Sasha never shared any of her interests. On Anne's birthday, Marcy discovers a strange book in the library regarding an object called the Calamity Box, taking a picture of it. But then her parents text her back over to tell her that her father has gotten a job out-of-state, and that they were intending to move away. Marcy is distraught as she doesn't want to leave her friends and runs away, discovering the Calamity Box in a nearby thrift shop. To avoid leaving her friends, she decides to give it to Anne as a birthday gift, hoping that everything about it was true and that they leave Earth. The three steal the Box together much to Anne's regret, and the three girls get sent to Amphibia.
Upon arrival in Newtopia, Marcy ends up falling down a flight of stairs and breaks a leg, being offered free public healthcare and meets King Andrias. She climbs into his pocket and gives him a gift, as Andrias forms a close bond with her. She is shown around Newtopia by Lady Olivia who tells her of her purpose of guarding nature.
In 'Marcy at the Gates', Marcy saves Anne and the Plantars from a colony of barbariants who are infesting the outskirts of Newtopia. They all decide to quell the infestation, yet Anne is concerned for Marcy's safety recalling her clumsiness. Yet Marcy proves her ability to fight for herself, and Anne and the Plantars stay in Newtopia for a while, while they also get to know Marcy more, as she and Andrias discover a hidden wing of the library. One night, Anne, Marcy, Sprig, and Polly have a sleepover like the ones Anne and Marcy had with Sasha, and they discover the ghost-like shadowfish in the basements of Newtopia. After Anne and the Plantars have an emotional time at the Newtopia Aquarium, Marcy decides to let Anne go back to Wartwood with them. Afterwards, Andrias offers Marcy a proposition: with the stones of the Calamity Box charged, she and her friends can spend the rest of their lives adventuring.
The three girls manage to charge all three stones, and return to Newtopia, where Andrias and Marcy begin to enact their plan. But Sasha and Grime betray them and they instill a takeover of Newtopia. But when Anne helps defeat them, Andrias reveals that his ancestors were not the scientists and explorers he said they were, but were actually conquerors who used the Box to conquer worlds until it was stolen a thousand years ago because of his friendships. Marcy calls him out for this, but he admits that he used her so that she may return the Box fully charged. He also forces Marcy to confess that she got Anne and Sasha stranded on Amphibia purposely because she didn't want to move away, breaking Anne and Sasha's trust in her. Feeling guilty, Marcy saves Sprig from falling to his death and uses the Box to open a portal back to Earth. Anne and the Plantars go through, but Andrias stabs her through the chest afterward.
After the battle, Andrias has Marcy placed inside a rejuvenation tank to be healed, as he has plans for her. In 'Olivia and Yunnan', Lady Olivia and General Yunnan decide to rescue her when Andrias' actions have resulted in the ruining of the ecosystem. They free Marcy, but are caught in a VR trap where Marcy is forced to relive her fears of being rejected by Anne and Sasha for betraying them. But the three manage to stop the VR trap, and Andrias stops them and introduces them to The Core, an AI construct consisting of a collection of Amphibia's greatest minds based on the shadowfish. The Core straps Marcy to a chair and uploads its consciousness into her body, possessing her in the process.
Upon her assimilation, Marcy has been placed inside a VR cubical pocket where she has been occupied with dozens of puzzles while the Core uses her body to plan an invasion of Earth. Upon the final battle in 'The Beginning of the End', the Core sets a trap for Anne, Sasha, and their allies where they discover that she has been assimilated, and he taunts them with the questionable nature of their friendship with Marcy. The castle makes its way to Earth where they begin their invasion, while inside her subconscious, Andrias' father, King Aldrich, introduces Marcy to a virtual reality of the fantasy setting Marcy always wanted to keep her occupied, accompanied by replicates of Anne and Sasha. But she discovers that it's not real when she learns that these replicates are programmed to love what she loves, which is not what the real Anne and Sasha want. Even at the risk of moving away, Marcy rejects the Core's fantasy and gives hope that Anne and Sasha will save her. Anne and Sasha reunite, and Marcy apologizes for everything she did, and Anne assures her that no matter what, they will still be friends.
Later, they return the castle to Amphibia, but the Core Helmet assimilates Amphibia's moon intending to ram it into Amphibia, as Marcy claims it's doing it because it's afraid for its own existence. The three decide to channel the stones' power one last time and they all get powers, but not before Mother Olm warns Anne of a contingency plan of using a secret spell that will destroy any foe at the cost of the user's life. When the Core proves too resilient, Anne takes the other two stones, sends Marcy and Sasha away, and activates the secret spell, losing her life in the process. Yet she is returned to life, and offered shards of the stones to return home, but only for a one-use trip, meaning she can not return to Amphibia. After saying their farewells to Amphibia, they return to Earth.
10 years later, Marcy still moves away, but returns to LA for a visit by the airport and reunites with Sasha, revealing that she has been making web comics.
Role in the series
In her starting days in Newtopia, Marcy started out blank in personality until she could get used to the new world. She searched Amphibia for Anne and Sasha, but due to the storm taking place at the time, she couldn't do it well. She soon gains a partner named Otto, a young eastern newt whom Marcy stands up for and ends up exposing a conspiracy from a California newt named Cadoc, who had discovered Andrias was up to something, but did not have the full context, getting him exiled. In time, she returns to her original self, which seems to draw Otto into falling in love with her, even if he didn't want to. Soon, Marcy decides to spend Otto's birthday bringing him on his first adventure with Anne, Sprig, Polly, and Hop Pop, to the Grand Temple of Wit when Rotteen tells them that it will bring the Gem of Wit's true potential out, unaware that she planned it to use the Calamity Box for her own plans. After the Season 2 Finale, she was not truly injured, but rather most of her consciousness was transferred into a new body made from a lock of her hair by Dava Typhon, the princess of Newtopia. Despite feeling guilty for all the hardship she put on her friends because of her bad Earth circumstances, she wants to help Dava restore peace for Amphibia and all the other worlds of Rotteen's friends by forming an alliance with certain Newtopians like Otto and his father Sir Kaiden, Lady Olivia, General Yunnan, Nev, and also Bracket and Valeriana, starting with visiting all 8 outside worlds and bringing the 8 friends back together while Sasha and Grime form a resistance against King Andrias, who is in truth not of conqueror descent thanks to the lies of his Bestiaran God master Extinctus, which includes the people of Wartwood. She also gains a team of friends like Rotteen in the form of a mandrill named Eshe Palmer, a rude and wisecracking gecko named Jako Waals, an often clueless and hopelessly misunderstood macaw named Rebelle Chromegood, a green sweat bee and former superhero named Gogo Stamen, a timid sarcastic fringehead named Clench Blanches, a gloriosa lily former cop named Gloriana Blume, a hotheaded Amanita jacksonii mushroom named Amara Jackson, and a shy and semi-mute calanoid copepod named Snap Podox. But she would eventually have to return to the tank upon learning that Extinctus knows about her adventures, only to fall into a trap. After being possessed, Marcy is still able to fight for control against Extinctus, and even manages to cut part of his power over the other eight worlds when Sasha begins to get her power back and allow her greater power, which results in Extinctus declaring war on all of them and ravaging their lands.