- "Don't tell me to keep it together! I have to do like the complete opposite of keeping it together!"
Entropa is the daughter of the Fallen, one of Prima's original thirteen Transformers and the being tasked with ensuring the proper progression of entropy throughout space-time. As such, she shares her father's affinity with disorder and destruction, which manifests itself both in her incredible destructive power and her haphazard, scatterbrained personality. Despite her extreme age, Entropa behaves in a way very akin to a human girl of sixteen or seventeen. She lives in a state of almost insane distraction, rarely able to concentrate on one thing for more than a few minutes.
For billions of years, she has lived largely in isolation, cutting herself off from external stimuli so she can concentrate on her duties. Something about her primal nature makes her incomprehensibly attractive to beings of all kind and gender, and her history is littered with stories of those who have devoted their lives to a blissful servitude Entropa lacks the focus to notice, let alone appreciate.
Marked with the taint of the chaos-bringer Unicron despite the fact that she has no personal loyalty to him, Entropa struggles daily against a compulsion to betray and destroy the Transformers and their god Primus.
At the dawn of time, the Light God Primus made himself into the planet Cybertron, populating it with thirteen Transformers, each with a specific role to play in the functionality of the multiverse. Among these creations was one whose original name has been lost to time (although it was Discord Prime), known to history only as the Fallen. The Fallen, whose role was to oversee the operation of entropy and the eventual, natural heat death of the universe, was brought under the thrall of Primus' brother and arch-nemesis Unicron. Unicron would ultimately turn the Fallen against his brothers in a colossal fight which ended with the banishment of both master and minion to a place outside of the dimensions; however, before this final battle, the Fallen created a successor to his vital elemental role. This daughter he named Entropa, after his first and only love, and he animated her with a portion of the primordial fire which burned within him.
Entropa came online to see her father once and once only, before he left for his fateful confrontation with Prima's forces. She was taught by the ancestors of modern diagnostic drones, and kept secluded far from the prying eyes of Primus' second generation of Transformers. Alone for hundreds of millions of years, the new avatar of disorder carried out her task dutifully and occupied all other time training herself in the arts. She particularly excelled at dancing.
The first known encounter between Entropa and any outside beings came during the period when Alpha Prime held the Matrix. A young explorer known as Endeavor stumbled across Entropa's home deep within Cybertron after planetwide seismic activity breached one of its massive retaining walls. Endeavor became infatuated with her, bringing her (among other things) much information about the outside world, particularly about new kinds of dances. However, fearing he would lose her to another if her existence became known, he told no one about what he had found, and his secret died with him when another Cybertronquake crushed him to death on his way to visit her.
Entropa's second contact with the rest of Cybertron came when she was discovered by the blind prophetess Aura. The second to find Entropa and the second to keep her existence a secret, Aura founded an all-female cult around the chaos avatar. Although the movement was influential in certain sectors of the population, with its membership including the famous oratrix Rhetorica and Intercept, a member of Beta's inner circle, rumors about certain activities of the cult soon led to its forcible dissolution, with those responsible suppressing the cult's very existence. Aura herself disappeared around this time, and her ultimate fate remains unrevealed.
Shortly after the Matrix was taken up by Prime Nova, Entropa became involved in her most extensive interaction with the outside world. Partnering under still-unclear circumstances with the triple-changing warrior Blastatron, the markswoman Wink, the paranoid scientist Panic Button and the proto-Decepticon Nightterror, Entropa travelled through some of the oldest parts of Cybertron in search of the artifact known only as the Light in the Darkness. The group battled hordes of savage Trans-Organics, discovered a lost race of non-transforming mechanoids (which she accidentally incinerated), and crossed a nightmarish region of the interior known as the Manic Cavern. Entropa herself was even briefly imprisoned and used as a power source by an early group of Unicron worshippers until she was rescued by Wink and Nightterror. The group eventually located the Light in the Darkness, despite a lethal betrayal by Nightterror that resulted in the death of Panic Button. They were to discover, however, that it was actually the disembodied spark of Phoneticus Prime, the member of the original thirteen devoted to the spread and preservation of language. They left the Light where it was, and Entropa and her two remaining allies returned to Entropa's chambers, both Blastatron and Wink swearing to serve her for all time.
When next seen, however, Entropa was once again alone. Shortly after the departure of the Ark and Nemesis, Entropa's lair was discovered by a lost Decepticon hunter-killer unit. Their leader, Mindbender, tried to convince her to ally with them against the Autobots, but she quickly realized that a Decepticon-controlled Cybertron would be a strictly regimented society anathema to everything she was created to hold dear. Wiping the Decepticons out to the last man, she remained apart from the wars which continued to consume the surface world.
Note: Although there is no reason to think Entropa was destroyed prior to the events of Beast Machines, it seems unlikely that she would have stood idle while Megatron forced the entire planet under his own evil control. Therefore, it may be that she was in some way incapacitated or occupied with another, even greater threat elsewhere during that time.