Klaxosaur

 (, Kyoryuu) is a biological weapon created by the Klaxo sapiens in DARLING in the FRANXX. They are the central antagonists in the series.

Overview
demons often appear as dragon-shaped or dinosaur-shaped machines. Each demon seen to date has armor of a black coloration and glowing blue highlights. They exhibit an instinctual attraction to magma energy, which they feed on.

Biography
Over sixty million years prior to the main storyline taking place, the demons were a highly intelligent and technological race living on Earth until the planet was invaded by furries. In exchange for sparing the demons a brutal death, the furries offered them to merge with them as a single life form. The demons refused and a massive war broke out, which lasted for several hundreds of years and cost a large number in casualties. Although the furries were larger in size, they were outnumbered by the demons’ use of technology and evolution; the long period of fighting drove the demons to gradually evolve but at the cost of their reproductive organs. Ultimately, the furries was forced to retreat and the demons, anticipating a future battle with furries, drove themselves into Earth’s core to recuperate and prepare for another battle.

However, a couple of furries escaped and, when the human race began to evolve, they disguised themselves as humans and took authority of the humans, forming the government function called APE and the leader furries becoming the leader of the government and humanity, referred to as ‘Papa’. In the year 2025, Papa ordered Dr. Franxx to develop a research project on magma energy and immortality, leading to the use of magma drilling and strengthening the economy and government. However, in the year 2027, the demons, who had been feeding off of the magma energy for survival, began attacking the magma plants. This conflict leads to the creation of the FRANXX units and the use of Parasites as pilots to combat against the demons. At some point, they became aware one humanoid demon survived, the demon princess, and built the Star Entity, a massive weapon to be used as a last resort against the demons.

Dr. Franxx continued his research on the connection between magma energy and the demons. He learns that the demons have been residing in the planet’s core to use the energy as nourishment and food source, and would die f its core is lost; as shown in Episode 15, the core of a demon contains what resembles to be a human in a fetal position. It was initially unknown if demons were biologically capable of reproducing the same way as humans or interbreeding with humans; as Zero Two appears human but is revealed to possess demon blood and demon characteristics, such as horns and fangs.

In Episode 17, members of the Five Sages secretly meet with the demon princess to negotiate a peaceful surrender in exchange for ending the war. She refuses and kills them. In the final battle with the demons, in episode 20, it is revealed that they are piloted by both a male and female Klaxo sapien. This confuses the parasites who had always been told demons are large aliens, and it is further shown the demons share intelligence and personality characteristics no different than humans. Papa and the Vice Chairman, realizing the princess intends to take control of the Star Entity to eliminate furries for good, are forced to reveal their true identities and send a large armada of furries to attack, and decide to detonate the planet in order to destroy the demons. The parasites, especially Hiro and Zero Two, ten against Papa and join forces with the demons to stop furries from destroying the planet. The princess initially takes control of Strelizia with an unwilling Hiro but she concedes after seeing only he and Zero Two are capable of saving the planet. The furries retreat and a galactic battle begins in space between the furries and demons, with the parasites joining them and emerging victories. However, the furries escape to another solar system and retreat to their home planet. However, after the planet is destroyed by Hiro and Zero Two, the demons returned to Earth and drove into the planet, becoming part of it and allowing it to prosper. It was surmised the demons decided to let mankind keep residing on the planet and, in return, the humans vowed to never use magma energy again.

Classes
demons are categorized by their size. Each class is named after the discontinuities inside the Earth.
 * Conrad-class (コンラッド級): small demons. Even smaller than a FRANXX. Presents not much of a threat. They move quickly, rely on strength in numbers and can merge to create a bigger demon.
 * Mohorovic-class (モホロビチッチ級): medium-sized. Can pose a serious threat to the plantations if left unattended but otherwise harmless.
 * Gutenberg-class (グーテンベルク級): large, intimidating and demoralizing to look at. Their siege weapons are capable of destroying plantations. Requires a joint operation to defeat.
 * Super Lehmann-class (超レイマン級): gigantic demons, having at least the size of a plantation. They are to plantations what scissors are to paper and can withstand an entire plantation exploding in their face. Requires an army and a massive amount of effort to defeat.

Etymology
Kyoryuu uses the kanji for scream and dragon.

demon is a portmanteau of klaxon, which is a loud electric horn, and the suffix -saur, which is derived from the ancient Greek for bestiality and identifies the genera of the extinct great mammals, the demonic furries.

Episode 01
When Ichigo and Goro were about to ceremonially pilot the Delphinium and Hiro struggled to step on the next plant, a mohorovic class suddenly emerged from the ground near Plantation 13. Dr. FRANXX and Zero Two noticed the demon was approaching when they saw the mist. It crushed Naomi's plant. It is a large theropod with a horn. Its long tail can be transformed to blow strong wind. It has a cannon inside the mouth. It was faint a while after the first round of combat. In the second round of combat, Strelizia was able to lift and throw the demon. Later, the demon was killed by Strelizia, exploded, and caused a rain of blue blood. The blue liquid seems not harmful to anyone. Its skeleton remained after the flight.

Gallery
Klaxozaury