Barf and Belch

Barf and Belch  is the male Hideous Zippleback owned and trained by Tuffnut and Ruffnut. Barf and Belch are like their owners, they have trouble deciding which head goes what direction and focusing on one target. However, unlike Ruffnut and Tuffnut, they can work together and find their owners annoying with their constant bickering.

Personality

Barf and Belch have the personality of a normal Zippleback; however, they have a laughable sense of humor. They enjoy doing the tasks Ruffnut and Tuffnut tell them to do, but they are in constant quarrel because of the fact that they sometimes have to listen to two different commands they are unable to do. Despite this, they usually help the Twins with their pranks. Barf and Belch often get annoyed with their riders constant bickering- which once led to them going wandering around Berk after the twins started issuing contradictory commands to each head- but both are willing to protect their riders at any costs. For example, when Torch first approached Tuffnut as an adult, although the dragon only stayed because Belch didn't want to leave him, both were willing to fight what appeared to be a wild Typhoomerang in order to protect him and they left the cave that they were supposed to stay in during Astrid's harsh training session to find Ruffnut who they felt was in danger. They are very in sync with their riders, mimicking several actions of them, such as their 'high-fives' and affectionate headbutts. They have also been seen fighting at the same time as their Riders are bickering.

Appearance

Barf and Belch have the appearance of a normal Zippleback. Despite the head's resemblance towards each other, there are minor differences that each head has. Barf has a slightly curved horn as opposed to Belch's horn which is straighter. Barf's longest teeth are in the back of his jaw and Belch has his longest teeth in front of his jaw. Barf's skin is also slightly more lighter than Belch's. The skin color and tooth differences disappear by the time of the second movie (from what has been seen in images, this is most likely a production goof). Barf and Belch are 66ft long, have a 38ft wingspan and weight about 6,036 lbs.

In How to Train Your Dragon

Barf and Belch were one of the captured dragons used to train the Viking Teens. The lesson they taught was to work together to find the head that lit up the gas (which was Belch). Later, Hiccup manages to get Ruffnut and Tuffnut to bond with them in time to help defeat the Red Death.

At the climax of the film, Ruffnut and Tuffnut, along with the rest of the Viking's teens, were on dragons. They helped the twins distract the Red Death to allow Snotlout and Fishlegs to attack them. By the end of the movie, the twins are seen riding Barf and Belch along with the other Viking Teens.

How to Train Your Dragon 2

Barf and Belch briefly appear being ridden by their riders, Ruffnut and Tuffnut. Barf in particular shows annoyance and slight aggressiveness when Snotlout approaches Ruffnut to flirt with her. Their were also seen to be very upset about Stoick's death. In the end, their rejoin back to their owners while both heads were trying to get comfrot by Ruffnut but she rejected Belch but Tuffnut quickly grab his head to be happy to rejoin together.

Abilities and Skills

Barf and Belch seem to have the normal abilities of a regular Zippleback, although some of their abilities and gain skills are heightened due to training under Ruffnut and Tuffnut.

Strength: Barf and Belch are seen to be able to lift up heavy objects with their claws. Both claws can lift up a weight of two heavy grown adult Vikings. They didn't budge when Toothless tried dragging them off the roof and they can carry heavy Vikings on their neck, like Fishlegs. Barf and Belch have strong jaws, but can hold back their full strength.

Acrobatics: This is seen in the battle against the Red Death, when they manage to avoid sudden bursts of fire. Despite claiming that Zipplebacks are bad fliers, they are surprisingly agile. They have a very flexible body, but they can tangle their neck by accident.

Speed: Barf and Belch have the speed of an average Zippleback, but they were also able to catch up with the Skrill, although the Skrill had been slowed down slightly by Stormfly and Toothless.

Gas and Spark: Barf is able to breath a large amount of green gas. This gas confuses and disorients people, with the exception of the Thorston Twins. Belch is able to release an electric spark. When combined, they can make a large explosion. There are able to use this to make protection for Astrid and Stormfly.

Stealth: Barf lets out a green, thick gas, which they use in order to hide. From there, they sneak up on unexspected enemies or prey, attacking them.

Intelligence and Communication Skills: They always know when their riders have gone too far in fighting and often take charge if they are in trouble. But, like their riders, they often fight with one another. Despite having learned hand signals, they occasionally misunderstand it. Like all Academy dragons, including Torch, Barf and Belch are trained in the basics of hand signals. Although, Barf will only obey Ruffnut's hand-signals and Belch will only obey Tuffnut's hand signals, though at first it was hard for them, but their trainers finally work as team to become successful against theirs enemies.

Endurance and stamina: Endurance and stamina, as was demonstrated several times shown to be good for their kind. They are shown to still get up after getting hit by the Skrill and Night Fury combination attack from falling in high speed on sea stack to be able to fly well. Even got back on their feet from getting hit by Typhoomerang from a distance.

Trivia

• Barf and Belch were originally supposed to be ridden by Fishlegs, and he briefly rode on Barf after the dragon flew away without the twins, along with Snotlout, who rode on Belch.
• While the dragon is male, Barf and Belch are commonly referred to as "them" or "it," most likely due to the two heads being individuals. The only episode where they are referred to as "he" is Dragon Flower.
• So far, Barf and Belch is the only one of the Academy dragons that Hiccup hasn't ridden at least once. 
• Barf and Belch are the only known Zippleback that has riders, this might be because you need two of them, in this case, Ruffnut and Tuffnut.
• The difference in the color of skin between Barf and Belch is probably a production goof, like the changes in tooth length.
• In the How to Train Your Dragon Movie, when they were approaching Hiccup, Barf and Belch spread their wings and start hissing, which is similar to the behavior of the Dilophosaurus in the movie, Jurassic Park. Barf and Belch are never seen doing this again.
• They seem to chase their tails when they are bored.
• Although Ruffnut and Tuffnut share Barf and Belch, Tuffnut seems to be closer to both heads overall; when he was briefly trapped with only Barf and Belch for company, Tuffnut expressed regret that he and Barf didn't socialize much, but in How to Train Your Dragon 2 Ruffnut actively shoved Belch away in favour of welcoming Barf back after Toothless defeated Drago's Bewilderbeast. But she probably cares about both heads.
• Barf and Belch will meet
• Barf and Belch guest star in