Hideous Zippleback

The Hideous Zippleback appeared in 2010 movie called How to Train Your Dragon. The Hideous Zippleback is a large Mystery Class (formerly Fear Class) dragon that first appeared in How to Train Your Dragon.

Of all the dragons that inhabit our world, one of the most unusual and dangerous is the Hideous Zippleback. The Zippleback is one of the largest dragons you may ever encounter. It's unmistakable with its twin heads. The heads are distinct, with separate thoughts and different personalities. Like most dragons, Zipplebacks can fly, but their wings are small and they spend most of their time on the ground. Zipplebacks are solitary, preferring to hunt alone. They come out after sundown, prowling dark forests for victims. The attack of a Zippleback is like no other. Instead of breathing fire, a Zippleback makes explosions. One head BREATHES gas, and the other head lights it.

The Hideous Zippleback is often described as one of the most unusual dragons in the world. This dragon has two long, serpentine necks with rounded spikes on it. These spikes can 'zip' together, in order to create the illusion of one neck. At the end of the necks, are two short heads. The Zippleback has a large horn on its nose, and two thinner horns on top of its head. Like most dragons, they have yellow reptile-like eyes. The teeth in their lower jaw seem to be longer than the ones in the upper jaw, sticking out. They also have two tails, which can also 'zip' together. The end of the tail posses a fin-like structure on its tails. The official website stated that thanks to its relatively short legs and wings, the Zippleback is a slow walker and flier. Despite this, Barf and Belch has been seen flying quite fast. Their legs possess short, but strong legs with four sharp claws. The Zippleback is probably one of the longest of the medium-sized dragons, if not the biggest.

According to the Dragons: Rise of Berk mobile game, Zipplebacks have only one heart and thus, it is highly likely that they have only one set of internal organs, except for the heads, necks, and tails.

The dragon has two personalities and two minds, one in each head, and often different ideas, thoughts, and personalities causes the Hideous Zippleback's heads to argue with each other over what to do. This dragon reminds some Vikings of bickering siblings when they aren't running away from it. Occasionally the dragon forgets that it is a two-headed dragon, and one head tries to go one way, and the other head tries to go the other way, this can be problematic. Even baby Zipplebacks fight over which direction to go or what to do.

It has been stated by Gobber that once this dragon is saved by a Viking, they must pay their longtime debt. They are willing to do everything to show how grateful they are of their savior by giving them fish or affection. This could be another way of training a Zippleback or any other dragon species. As Barf and Belch have proven, they will even leave their old riders behind to stay with another for his entire life until they return the favor.

It's shown in a training addition to How to Train Your Dragon that Hideous Zipplebacks (and other dragons) have a sense of humor; when a Hideous Zippleback attacks Ruff and Tuff while the two twins fight, the heads grin at each other as the Twins continue to fight dangling from the Zippleback's mouths.

Powers and Abilities

 * Gas & Spark: The head on the right side breathes a green, flammable gas, while the left head produces an electrical spark from its mouth to ignite the gas, creating lethal explosions, small fire bolts, or large fire 'walls' to contain their enemies. By itself, the gas can make a human disorientated if inhaled, as shown by Fishlegs. Zippleback gas can also be used to determine the location of anything that is covered by molted Changewing skin, because it will go around the solid object. This will give the appearance of an 'empty space'.
 * Stealth: Hideous Zipplebacks can use their gas to hide in, which makes them very stealthy. They use it to unexpectedly strike their victims. The gas acts a smokescreen, obscuring their movements.
 * Flaming Ouroboros Formation: This special ability of the Hideous Zipplebacks consists of releasing a large amount of gas and then setting themselves on fire. They bite their own tails and become a flaming wheel or ouroboros, which they can use to knock out enemies. It is likely they have to be taught how to use this ability, however.
 * Venom: In the first movie, Fishlegs stated the Zippleback's venom is injected for pre-digestion, which may mean that they have a weak digestive system. However, the stats in the Dragonpedia say that the Zippleback has no venom at all.
 * Speed & Agility: Despite the official website claiming Zipplebacks are poor fliers and walkers, Hideous Zipplebacks have shown to be quite agile and fast. This was demonstrated in the battle with the Red Death and later also multiple times in the series. Therefore, it is safe to assume that the Zippleback is actually a quite agile and flexible dragon, although nowhere being near the fastest.
 * Endurance & Stamina: Zippleback is able to endure the attack of a Typhoomerang and still able to get back to try to continue the battle, as they have a large amount of stamina on their side to continue long flights to catch up with other dragons.
 * Climber: Hideous Zipplebacks have shown to be great climbers as Barf and Belch have shown in the episode, "We Are Family, Part 1" as they are able to climb terrains very well.
 * Hunting: These dragons are solitary hunters that prefer to hunt as an ambush. Since these dragons have great stealth as they will use their gas to trap their prey in and able to do sneak attack. They even able to hunt well in the bushes in the forest as for ambush hunt.
 * Strength & Combat: Zipplebacks have proven to be very strong as they are able to tangle their necks together to carry the weight of Gronckle, Fishlegs, Tuffnut, and Ruffnut without too many difficulties. However, a single neck of a Zippleback, as shown by Barf, isn't capable to carry a very heavy rider. They even showed some of their strength to hold their ground against Toothless.
 * Intelligence: While growing, hatchlings are stated in Dragonpedia to have high intellect and problem-solving abilities, such as having one head watch for danger while the other watches for food, or managing to solve complex problems such as one head scaring the prey into the mouth of the other head. Barf and Belch have proven to be very intelligent at times. They knew to use the statue of the Eruptodon on Caldera Cay to stop the flow of the lava threatening to destroy the village, as shown in the Race to the Edge episode, "Defenders of the Wing, Part 2". They also knew to use their distress call when Hiccup was in trouble as well.
 * Transmitting Information: They have a special ability to simultaneously transmit information to both of their brains. For example, if one head is covered up with a blindfold and food is stuck in front of the other head, both heads will start salivating at the same time, even though only one can actually see the food. With this special ability, it makes it nearly impossible to sneak up on a Zippleback. The two heads, however, still possess their individual thoughts and different personalities.

Weaknesses

 * Conflict between Personalities: The dual heads can be a vulnerability, as Drago Bludvist's forces were able to incapacitate a Zippleback by shooting darts into the neck of one head, knocking both heads out. The two heads have different personalities, and if they don't work together, it can be hard for them to do anything. They even slam into objects if both heads are not paying attention when chasing prey, as shown when a wild Zippleback chased Tuffnut into a tree. However, when Barf was stung by an immature Speed Stinger, Belch was unaffected and proceeded to drag around a paralyzed Barf who constantly emitted flammable gas.
 * Speed: Perhaps due to their larger size and relatively short but broad wings, Zipplebacks are slower in flight than some other species.
 * Dousing Spark Ability: According to How to Train Your Dragon, dousing the sparking head with water can short out the fire starting ability, leaving the Zippleback unable to light up the gas from the other head.
 * Loud Noises: According to a short Zippleback training video from DreamWorks Animation, the Hideous Zippleback can get confused with too much racket and loud noises. The racket may also agitate the dragon.