Below are types of Strike Class dragons stated in the movie, the show and the video game. If I missed any, don't hesitate to PM me.
Common dragons are allowed by any members, while the rare can differ between Mods and Admins
Legend:
T=Trainable
UT=Untrainable
UK=Unknown
Level 1=Very Common
Level 2=Common
Level 3=Uncommon 100 posts and up (Also, mods and up)
Level 4=Very uncommon-350 posts and up (Also, mods and up)
Level 5=Rare-400 posts and up-Must get permission from an admin or mod (Also, admins and up)
UR=Ultra Rare-Only admins are allowed to make these, and even then they must have at least 500 posts, the dragon can only be used for site events
Strike Class 
Strike Class dragons have blazing speed, pin-point accuracy, vice-like jaw strength, powerful attacks and extreme intelligence. All strike class dragons utilize lightning in their ranged attacks (Skrills absorbs lightning and fires it; Night Furies breathe plasma: a mixture of fire and lightning) Dragons in this class are the rarest of all, are near close to extinction, and also the most difficult to train, but the most loyal once training has been accomplished. Toothess is used as a symbol for this class.(you can tell because the tail is missing.)
Skrill UK Level 5
This incredible creature has large wings, a spiked back and tail. The spikes on the Skrill's back and tail are sharp enough to cut with the slightest abrasion, and it is an excellent flyer. It also appears to have shark-like gills on its neck. It slightly resembles a Thunder Drum, and its head also resembles that of a Deadly Nadder. It apparently resembles a Night Fury in flight and rivals its speed, being slightly slower. When a Skrill is riding lightning it seems to wrap itself in its wings and dive down. Like the Monstrous Nightmare, it uses the large claws on its wings to walk and run on land. Find more information at Dragon Anatomy.
As with most of the dragons in the manual, it is listed as being "extremely dangerous" and the manual instructs readers to "kill on sight". The Skrill electrifies itself when hunting. It also rides lightning bolts to reach supersonic speed. The Skrill is only found during lightning storms. It can breathe out concentrated beams of powerful electrical white fire. Skrills can also store lightning in their bodies and use them at another time. It can also survive for decades when frozen due to its inner body temperature
Night Fury T Level 5
The Night Fury is the rarest and most intelligent of the known species of dragon. It is small to medium-sized with a sleek, dark body with varying shades of a navy blue coloration. It sometimes appears bluish and has faint lighter patterns similar to that of a manta ray. The Night Fury has two pairs of wings with a shape similar to a bat, two mobile, ear-like plates on the back of its head that show its mood, a second pair of plates in between each ear-like plate, two just behind the jaw and beneath each ear-like plate, a pair of large, yellowish-green, cat-like eyes and sharp retractable teeth. Unlike most dragon species, the Night Fury has a short neck and lacks any kind of horns.
In flight, the Night Fury's wingspan is unrivaled, making it resemble some sort of jet plane. This allows it to fly faster, longer and further than any of the other dragon species. It uses the wing-like flaps on its tail to steer and maneuver, similar to an airplane rudder. However, a Night Fury will be incapable of flying if one of these flaps is missing or destroyed. Not only is this species fast in the air, but it is also very fast on the ground, running very fast on land and can even leap from tree to tree.
Night Furies are generally quite aggressive to any form of threat they find, similar to how the other dragons treat the Vikings of Berk. According to the Dragon Manual, the Night Fury is considered to be so aggressive that it is likened to the "unholy offspring of lightning and death itself".
However, like their fellow dragons, Night Furies are seen to have a different personality when they are not threatened. They are curious creatures that attempt to understand new things they observe and are intelligent enough to attempt to recreate the actions that they see. Night Furies are fairly capable of communicating, seemingly understanding human speech. They also have the ability to use echolocation. When Night Furies are at locations where their visual sight is limited, making it dangerous to fly, they can use a special roar. This roar, visualized as a purple colored sound wave from the dragon's perspective, bounces off all objects and obstacles nearby and allows the dragon to avoid them, even in mid-flight. Unlike with bats, this roar, or at least part of it, is still low enough to be within human hearing range; humans are able to hear the dragon using the roar.
A Night Fury's main type of attack style is dive-bombing at enemies at great speed while being completely camouflaged within the dark sky. The Night Fury is able to become completely invisible at night because of its dark colored scales. In addition of dive-bombing, the Night Fury will also spit out oxygen/acetylene-fueled flames that will explode upon impact and will instantly incinerate anything. Night Furies are picky eaters and will only eat fish. When hunting, a Night Fury uses its sharp retractable teeth as fishing hooks in order to snatch and grip prey from the water. Night Furies are also capable of completely swallowing prey whole and their stomach liquids, which are similar to battery acid, are strong enough to dissolve fish bones. When tamed, Night Furies are known to regurgitate half of their catch for their owners. While Night Furies usually keep to themselves, they are very protective. The Night Fury is a very dangerous and elusive dragon and should be avoided at all costs, unless of course, one is able and willing to train it.
Night Fury's are said to be amazing fighters. They use their incredible explosive fire to damage any unlucky foe. It is shown that a Night Fury can switch between different fire styles. Plasma blasts are purple fire-bolts that explode on target almost instantly. These are a Night Fury's primary defense and are very lethal. Second is the fire a Night Fury uses to warm up the place where it will sleep. This fire isn't particularly strong, but it can light up fireplaces and stoves. Night Furies are very agile and swift in flight, using this to confuse their enemies.
Unofficial: (Original)
Razor Belly T Level 4 (Green, black, grey)-level 5 (red)
The Razor Bellies can be four different colors. The green, black and grey are more common than the red. This species is skinny, but its tail, legs, and wings a very muscular. Their body is very smooth and not too detailed, so it doesn't stand out too much, except for its glowing eyes. Also, because of their small claws, their firepower is rather high and their tail can be used as a heavy whip.
The young usually start out as white with a growing shade of their coloring. As a young dragon, they are very skinny and their tail is really the only defense they have since their scales on their belly haven't quite sharpened yet. Their claws haven't formed quite yet.
Razor Bellies are particularly quiet with an aggressive attitude when threatened. But when it's in a situation it likes, it will be a happy, loving dragon that enjoys snuggling quite a bit. They have a bad habit of being afraid of spiders or insects. As well as falling mid-flight. They generally like bread, and don't like crab. Their short claws are made up for by using their tail as a weapon. Or even laying on their back and exposing their stomach so the enemy can't get to them without gaining a few deep cuts.
The Razor Belly makes clicking noises when it feels like it's in trouble or when it's feeling ambitious. The Razor Belly can use two different types of strikes during a battle. It can either fire balls of pulsating energy (usually a green or blue color) that can burn and throw an enemy a few feet, or balls of fire that can light a building or opponent on fire temporarily by engulfing it in flames. The Razor Belly can make the scales on his/her belly stand upright to act like barbed wire. But if you step on the scales or land on them, they will break off and it usually takes a few hours for them to redevelop. The species usually resides in wetland areas or barely lit landscapes.
Halycon Guardian T Level 3
The Halycon Guardians are a happy species, as well as protective. On their heads is one set of curled, slightly gnarled horns, and they have a little bit of fur on their necks. Their wings are long, and unusually feathery instead of the usual leathery or scaly texture. The feathers are long and always well-kept, and if one falls out it also grows back very quickly. It is considered a good omen to find one of the feathers, as they bring good luck. On their back legs and where the tail joins the body is another patch of fur. At the end of their long tails is also a small patch of feathery down, and their claws are long and strong. They always have blue or green eyes.
The Halycon Guardians adore eating anything from the earth. They love berries and fruits, and especially sugar. However, they also do enjoy fish and bird meats. They love to fly, and also love the sunrise and sunset. They hate any sort of beef, pork, or chicken, and tend to dislike reins or any sort of rope. They do not like storms. They all fear battles, preferring to stay well out of the way. They have weak underbellies, and some parts of their body do not have scaly protection.
Halycon Guardians are nicknames "Angels" for a reason. They are extreme pacifists, and hate hurting things unless absolutely necessary. Some people rumor that they live in the skies, since they never seem to touch the ground and are always circling up above the Earth. They will protect anything and everything, and fight for what the consider right and wrong. They tend to be very hard to win over - they have a very good sense for truth and lies - and believe that actions speak louder than words. If you gain their trust, however, then they will fight til the death for you, no matter what.
Their nimble bodies make them amazing fliers, and they are capable of reaching high speeds and performing difficult maneuvers. They are also able to have extreme emotional connection with their trainer. It is said that if you spend long enough with a Guardian, then you will build a bond with them nothing can break. They will be able to sense what you want before you do, which is why they do not require reins to guide - a simple nudge of their body will do.
They are very protective of what they care about, and this natural instinct means they are often hurt because of it. However, this does not seem to affect them as they can heal very quickly. They a very social creatures, and love interaction.
The Halycon Guardian has long and sharp talons, that they can use to rip and enemy to pieces. Their fangs are long and sharp, and they only use them as a last resort because they hate the taste of blood and the feel of warm, pulsing flesh. Their primary weapon is, in fact, their wings - they are long and powerful, and they use them to send strong gusts of wind onto their opponents or to evade them.
They can pick things up with their talons, and use this ability to gather stones and rocks and drop them on enemies from high above, their keen eyesight meaning that they almost never miss. This is the most passive way to fight, and, to them, it is the most preferred. It can heal and recover from wounds very quickly, as long as it is able to rest and is not put under any further stress.
These dragons are found most commonly on high, lofty areas, such as snowy mountain peaks or high jungles and trees. Sometimes, they can be found wandering forests, but very rarely - they are more associated with the clouds and sky.
