Seashocker

The Seashocker appeared in 2014 movie called How to Train Your Dragon 2. The Seashocker is a medium-sized Tidal Class dragon that first appeared in How to Train Your Dragon 2.

Supremely furtive, Seashockers share attributes with many of the the ocean's most extraordinary creature: the morphology of a Manta Ray, the sonar of a dolphin, and the bioluminescence of a deep dweller. Similar to Hideous Zipplebacks, the Seashocker also possess two heads. But unlike their airborne cousins, Seashockers only have one thing on their twin heads: predation. If you ever see their dark fins amongst the waves, it's it's already too late for you - the rest of their pod has already moved in to attack! Being water-based dragons, Seashockers do not breathe fire. Instead, their bites paralyze victims with an electrical charge that stuns even the biggest prey into submission. Perhaps this is the reason why all dragons fear the Seashocker's closest evolutionary relative - the electric eel! Seashockers are wonderful ice-breakers, but not in the conversational sense -- their dorsal fins, comprised of super-dense cartilage, can cut through even the most frigid floes, allowing Seashockers to carve a path to any ice-bound prey.

The Seashocker looks similar to a blue Manta Ray, which is more noticeable when seen in a bird's eye view. It has two heads and has large a wingspan of 15 meters (50 feet) with two small flippers in front of it, giving it the appearance of a blue colored Manta Ray. The dragon also has small spikes lining its spine and the top of its heads. Their dorsal fins are very sharp and dense, functioning as amazingly powerful blades that are capable of slicing thick sea ices and even the most solid floes. Its necks are incredibly short. In total, the Seashocker's body shape strongly resembles that of a Manta Ray, with wings that extend perfectly straight out. This natural arrangement ensures great speed in the air or beneath the waves of an icy ocean.

The Seashocker lives in very deep, icy waters, where it can use echolocation instead of sight to hunt prey. It can also use its bioluminescence as an attraction to deep sea fish. But on some occasions, like the dragon's feeding time, Seashockers can appear near the surface where they can help the Bewilderbeast draw fish into its mouth by circling around. In return, some fish are given to them.

Their most remarkable feature would be their teamwork. They often hunt in pods and circle their prey into a tight 'bait ball'. They move swiftly together and use it both to hunt and care for their young. Seashockers will also work together to defend against predators, as seen in "Shock and Awe" where they use their own electrical shocks to drive off a pack of Scauldrons.

Despite a diet mainly consisting of deep-sea fish, Seashockers have been known to scavenge flotsam at sea, even if the 'debris' is a Human or a dragon egg, as seen in Dreamworks Press: Dragons. This behavior is mentioned again in Dragons: Rise of Berk, where it is outright stated that Seashockers of Bloodspilt Bay hunt and kill humans for food. Since the human subject in Dreamworks Press: Dragons is struggling to swim in the water and therefore emitting increased electrical signals, it is possible a Seashocker - like a shark - can be attracted to the human as possible prey in this manner.

Powers and Abilities

 * Firepower: Unlike the majority of the dragon species, the Seashocker possesses a unique ability to generate electrical discharges rather than the usual fire breath. Although it can emit electricity from its mouth, it will be released when it has bitten something, or in a short range just before it nips its target. Their electro-charged bites can take out even the largest enemies. Because of their electro-abilities, rather interestingly, electric eels are regarded as the closest evolutionary relative to the Seashocker, which may be the reason eels are feared by almost all dragons. The episode "The Eel Effect", however, suggests the reason dragons fear eels is because of eel-pox and is completely unrelated to the Seashockers. As seen in Race to the Edge, Seashockers are able to generate a field of electricity as a protection around themselves by joining their heads together. An electrical current can be produced by the snout of each head. When the electrical current joins together, it generates around an electrical field, similar to how the Skrill does. The energy released creates an electrical force so powerful, that even large creatures like Scauldrons, after being electrocuted, would be ejected away forcefully. It can also apparently eject from itself a human up to approximately 60 feet.
 * Hunting: Seashockers are also fearsome hunters, similar to Orcas in their lifestyle and intelligence, and are equipped with many weapons including dorsal fins, electric charges, and two heads. Hunting in groups, the Seashocker is an expert in the sneak attack. If you see its fin in the water, then the rest of its pod has already moved in to attack. Seashockers are often found hunting in packs or pods and have great teamwork. This helps them to take down large prey easily. They have also been seen herding shoals of fish into a Bewilderbeast's mouth by circling around it.
 * Echolocation: They use their echolocation to locate its prey in deep water like dolphins, porpoises, and whales. The underwater sonar they emit allows them to stealthily detect prey. They use this ability to travel in the deepest depths.
 * Bioluminescence: The Seashocker also has the ability to glow in deep dark waters where the light doesn't reach thanks to its bioluminescence.
 * Dorsal Blades: Their dorsal blades are very powerful and sharp that they can cut through the thickest sea ice. They are composed of super-dense cartilage, which allows them to cut through floating sheets of ice to get to their prey.
 * Speed & Agility: Seashockers are fast and agile enough to outmaneuver Scauldrons, as well as to ambush its prey. According to Fishlegs, Seashockers move too fast for the human eye to see them.
 * Strength: Seashockers are strong enough to pull boats occupied by humans, as well as carry humans and other dragons on their backs, showing no signs of struggle.
 * Diving: Seashockers are able to dive extremely deep in search of their preferred prey, small, deep-sea fish. In order to do so, it is likely that, like many other deep-diving animals, the Seashocker possesses several specialized features to withstand the pressure of the deep ocean. These features include a heart that can decrease its heart rate, collapsable lungs and ribcage that can reduce air pockets, expel 90% of the air inside of the lungs, and decrease their buoyancy, blood and muscles that can store oxygen, the ability to cut off the flow of oxygen to nonessential parts of the body, the ability to limit movement, and the ability to shut down breathing, digestion, kidney function, and liver function. With these abilities, the Seashocker may be one of the deepest divers of all known dragon species.

Weaknesses
The Seashockers' shocking ability produces an electric pulse that Scauldrons can sense, allowing them to track down and prey on the former. Like many Tidal Class dragons, Seashockers cannot last for a very long time out of water and will quickly dry up. Furthermore, unlike other Tidal Class dragons, Seashockers lack legs and on land are as helpless as a stranded whale. In addition, despite possessing wings, Seashockers are very weak flyers, as their wings are designed to be more like paddles for swimming in water. This is why Valka's Seashockers brought Toothless to the shores of Valka's Mountain and gave him to Sailback instead of flying him up themselves.