Wyvern

The Wyvern (ワイバーン) was an artificial creature created by a Biohacker, which was featured in Toaru Majutsu no Index SS: Biohacker Arc.

Etymology
A is a type of dragon, usually winged and bipedal (often with just two limbs), found in European folklore and heraldry.

Appearance
The Wyvern was around 10-13m tall, about the height of a three-storey building  Immediately bringing a dragon to mind, it had a reptilian body, resembling a bipedal carnivorous dinosaur, with scales like those of lizard (green initially) and thin bat-like wings growing from its back. Its head was larger than that of a giraffe, with forward facing eyes (reminiscent of a cat's eyes) and a maw of fangs. It also had a thick tail.

Principles
The Wyvern was an artificial creature created as a living weapon, with Academy City's biological science and technology being abused to rearrange DNA from existing animals and piece them together as desired by its creator. It had genetic material and biological traits from multiple animals, but its structure was primarily that of a reptile, with elements of a bat.

Aside from its general appearance, the Wyvern had another trait associated with dragons, in the form of a fiery breath. A flammable substance, like methane or alcohol, was generated inside the Wyvern and then mixed with the oxygen in inhaled air, before being ignited and fired from the Wyvern's mouth, in a manner similar to a flamethrower. Extending in a line about 50 meters long, the attack could liquify asphalt and melt steel stairs, with temperatures exceeding 1500 degrees depending on the oxygen intake. Sparks and an orange glow in the Wyvern's open mouth gave a early warning for the flamethrower attack.

The Wyvern had an armor of hard scales over its thick muscles, capable of changing their color to match their surroundings. The angle of the scales could be adjusted to divert radar waves, so that they would not return to their source. They were also able to neutralize ultrasonic and infrared targeting. The Wyvern's wings, derived from those of a bat, enabled it to at least scale multi-storey and similar heights. It also had an ultrasonic sonar which could be used to scan the surrounding terrain in the dark.

Despite the combination of existing animals giving the Wyvern tremendous strength and useful traits, it also inherited weaknesses possessed by those creatures. As the Wyvern's internal structure was largely that of a reptile, it was vulnerable to cold, in much the same way as cold-blooded snakes and lizard are. Unable to maintain its body heat, a rapid cooling could threaten it, with a loss of functions such as its camouflage and a forced hibernation as its body temperature was reduced. This vulnerability to cold was used in controlling and transporting the animal, inducing artificial hibernation so that it would not devour its controllers.

The Biohacker controlled the Wyvern's movements by using a bow (with a stabilizer and dot-sight attached) to fire arrows with material coated with specific substances, releasing the substance into the air in order to guide it. As the Wyvern was a lower-thinking lifeform, much like reptiles or insects, its actions were determined by a series of yes/no questions, with answers determined from the information gathered from its surroundings, moving it along the optimum path. Knowing the conditions these thought processes were based on, the Biohacker could manipulate them to control the Wyvern through the different arrows. A downside to this method was that it required considerable effort and any mistakes would cause a large spread of damage outside of the intended area - as such, the Wyvern was used when a target needed to be taken out regardless of the cost.

Background
The Wyvern was secretly created by a Biohacker affiliated with L.S.S., using an illegal application of Academy City's biotechnology, and used by them as a weapon.

During the summer of Kamijou Touma's third year of middle school, the Wyvern was deployed by the Biohacker after the thugs he had paid off failed to deal with Mitsuari Ayu, after being transported in a frozen container on a L.S.S. truck. Touma and Mitsuari, together with Kumokawa Seria, were forced to flee from the Wyvern, with Touma's Imagine Breaker being useless against the Wyvern as a product of biotechnology rather than supernatural power. However, after they deduced the creature's inherited weakness, Touma managed to neutralize it with water from a firehose, cooled and pressurized further with dry ice from a nearby cake shop (added according to Kumokawa Seria's calculations), forcing it into hibernation. The girls tracked down and dealt with the Biohacker, who was subsequently programmed by Mental Stinger to run right into Touma's fist.