The Core is a mysterious entity and the main antagonist of the 2019 Disney animated series Amphibia.
Not much is known about its personality but it shown to be quite malevolent in nature and craves both knowledge and power. It is quite particular when it comes to choose a host for its consciousness and would only settle for the most intelligent beings.
Not much is known about its past but it was created after studying the Shadowfish so the greatest minds of Amphibia would be preserved forever as they would be combine into this robotic entity.
In the Season 2 episode "The First Temple", The Core is introduced as Andrias enters at the end stating that the prophecy is being undone as they speak and that they will have their revenge as it opened its 13 eyes.
In the Season 3 episode "Olivia and Yunan", Olivia, angered over Andrias' tyranny and disrespect to nature, decides with Yunan to rescue Marcy from stasis so that they can create a plan to defeat him. They traverse the castle's many passages and briefly come across the Moss Man. Soon, they manage to find Marcy and revive her, but are all trapped in a hologram that preys on their worst fears. After overcoming the illusions by destroying the source, Andrias appears and reveals that they used the Moss Man to revive Marcy, and had used the Shadowfish to learn how to conquer death long ago and create The Core with it as it is the collective intelligence of eight of Amphibia's brightest minds, and that Marcy's intelligence was what was needed for an entity called the Core to be rebirthed. The Core transfers to Marcy's body, taking her over.
Role in the series
In the SAFA timeline, The Core is revealed to be the life support of the last god existing in The Bestiary Dimension, the home dimension of Amphibia, and is specifically Extinctus, the Bestarian God of Natural Selection, Extinction, and Superiority. Eons ago, the Bestiary Dimension was inhabited by gigantic kaiju-like Elder Gods referred to colloquially as the Titans, who had created all worlds in the realm as well as a giant fiery salamander deity called the Salamander, which was much like the salamander in classic folklore, and was intended to be the incarnation of life itself. But when it did so out of control, the Titans separated it into what is now known as the Bestiaran Gods, making half of them good and the other half evil to provide balance. However, Mlandoth would soon arrive in this realm looking to turn the Salamander into his own pawn and be the first of a strain of Deviant Outer Gods set to upset the needed balance of Destructor Outers and to be a progenitor of such by producing interdimensional empires that serve under his command, intending to unite them all together by infecting the realm with Calamium, a bronze-gold metal from the Calamity Realm that can enhance anything it touches as long as it is in a calamitous state. But it changed the Bestiaran Gods into becoming so well-adaptable, they evolved an immunity to morality illness. This would further change them into being complacent, believing they were the most superior gods in the multiverse, and soon intended to share their superiority with other gods from other realms, and they decided to use King Echidian as the one to help them do it. But it would be foretold that the dimension would be destroyed because of this, and Extinctus refused to believe it, doing all in his power to prevent it. Instead, he only failed as the conquest of King Echidian, who built an unstoppable army from the combined power of countless worlds including half the ancestors of Andrias who were conquerors to start an interdimensional empire, starting with Anne Boonchuy, Sasha Waybright, and Marcy Wu's Earth. But shortly after their arrival, this resulted in the realm's destruction by a Xzar named Xestroyus. Later, the realm was restored by a Resurrectorate named Razeena, and after Echidian announced to the entire realm his curse which would prevent history from repeating itself by reducing all monsters in the realm into an animal intelligence and forbidding any accumulation of powerful magic, blaming both sentience and magic for their realm's destruction. As a result, because there was no one left to believe in the Bestiaran Gods, and because the Outer Gods undid their immunity to morality illness, they began succumbing to it and dying left and right. Thus two gods remained: Extinctus and the Prophet Goddess Hophia that foretold of the destruction. Fed up and feeling like, as gods, they were too weak to do anything, especially since his brother died giving up on everything, the madness drove him off the edge. After his kind all died out, he arrived in Amphibia succumbing to the morality illness plague, and yet managed to find his salvation by meeting a cult that still believed in him. With his life saved, he swore to use the Calamity Objects to enter the Nothing Dimension and destroy all Xzars starting with Xestroyus, not aware that he has been infected by Mlandoth to be the seed of the Bestiaran Gods' restoration into the Salamander via his destructive revenge onto the Xzars and plans to use the Calamity Box to undo the initial destruction of the Bestiary Dimension. His endeavors spanned countless generations and he had many pawns and enemies, and sacrificed so many people with his cult, which would come to be named The Salamander's Fire, and saved his own life further by creating The Core from the eight bright Amphibian minds who, in truth, knew of the upcoming Bondlink Prophecy in which nine worlds including Amphibia would merge with the same Earth King Echidian attacked beginning with Extinctus' destruction, as each individual mind studied each from their basements beneath Newtopia's palace, unknowingly for Extinctus. He would also spread eyes across the nine worlds in order to collect boundless knowledge and power, though the ones on Earth, whose deployment probe caused their Tunguska Blast of 1908, had taken control of all their country leaders after the two World Wars. These eyes would possess Newtopia's previous leaders, King and Queen Typhon, the eight leaders of Mammalia, Reptilia, Aves, Arthropoda, Cambria, Plantae, Fungi, and Protozoa, and would also possess others such as the parents of Valonia, and even the parents of Marcy around present day, as he possessed them because he was afraid Marcy would be one of the foretold heroes who destroy him. But a woman named Sariah LaStrange would use amnesia-inducing drugs to not only make them forget they were mind-controlled, but brainwash them into moving away after she offers Mr. Wu a job out of state. He would thus be the one who causes Marcy to run away and take Anne and Sasha to Amphibia, and the resulting climax of 'True Colors', in which he corrupting King Andrias after he refused to lie about his ancestors being conquerors, when they have all but renounced that past when Echidian announced his curse and joined the other half of the family who were peaceful explorers and scientists, and as punishment, crushed everyone's trust in him, and especially Marcy's by breaking his promise on letting her reveal the truth of what she did, and then control Andrias into stabbing her and use her as his new host. He would begin his quest to find the three girls and steal all the remaining power of the Calamity Box's gems since then and get what he needs to enter the Nothing Dimension and exact his revenge, and succeeds so far by corrupting Marcy into being his agent of destruction by telling her the half-truth about her parents being brainwashed. But thanks to her new friends, including a Newtopian frog named Spring Greene, she learns of his manipulation and manages to stop him from mutating her body into his former glory, but only for now. Extinctus is not only a cunning and strategic mastermind, but his tragedies and lifestyle as a death god have made him inhumanely cruel, sadistic, sociopathic, and vindictive to anyone who crosses him. He stops at nothing to achieve his goals, including killing people, destroying their hopes and dreams, crushing friendships, and committing terrorism and wanton destruction upon his enemies, seeing it as due punishment for their mistreatment and neglect for his people as he is unaware of what his kind used to be.