Night Terror

The Night Terror is a small Stoker Class dragon that flies in overwhelmingly large packs which appears in the series Dragons: Race to the Edge.

Appearance
Night Terrors are small dragons that are slightly larger than the Smothering Smokebreaths and the Terrible Terrors. Each individual Night Terror is black in color, except for the alpha. When they group together, especially at night, they appear to be all black in color and they form the shape of a larger dragon. They have small teeth and rounded tongue. They also have two small horn-like ledges on top of their nose. They also appear to have a short tail with four, short, thin spikes on the tail.

The alpha is white and slightly larger than the others. It appears as an eye of the large dragon shape in the swarm.

Behavior
As Night Terrors have the bit of persoanlty of bats. As they fly as conolny and are nocturnal.

Colony
Night Terrors are able to fly closely together in order to form the shapes of larger, more terrifying dragons for protection. This behavior resembles that of certain shoals of fish, who swim together in order to appear larger so as to scare off predators. Also, each swarm has an alpha. The alpha is able to control its fellow dragons and instruct them to form certain formations. They have been shown forming a Night Fury, Fireworm Queen and a larger Night Terror.

Speed
Night Terrors are incredibly fast and strong fliers, especially when they are together in a swarm.

Dragon Controlling
The alpha Night Terror can control smaller Night Terrors, organizing them into a formidable flock that appears to be a larger dragon when posed with the threat of oncoming predators.

Fire Breathing
A single Night Terror breathes an admittidly tiny fire blast. However, when a swarm of these dragons fires, the little shots can turn into a massive fire ball.

Intelligence
They are able to form a shape of other dragons, making themselves look bigger. They even figured out their own way to get rid of the Fireworms by forming themselves into the shape of a Fireworm Queen. It is possible they had never seen a Fireworm Queen before, but they had the idea to make themselves look like a large Fireworm, hoping they would be followed by the smaller Fireworms.

Titan Wing
Source: Dragons: Rise of Berk

Titan winged Night Terrors have grown larger and certain parts of their body has became blue. The ledges on top of their snout is longer and more wrinkly and becomes blue. Blue horn-like structures grow out of their neck and their claws grow sharper. Also, the spikes on their tail turn blue and their whole tail is longer.

Trivia

 * Originally, Tuffnut wanted to call the dragons "Smidvarg and the Gang".
 * The Alpha (white) Night Terror is named Smidvarg, which was given by Tuffnut, which corresponds to the name he wanted to give the dragons.
 * Their ability to fly in a large group is similar to Scarers.
 * The Night Terror is nocturnal in nature because its disguise as a larger dragon would fail if the predator saw the white of the Alpha and the outlines of all of the other Night Terrors in the daylight.
 * Night Terrors are often used as sentries on the Dragon's Edge because, although they can be quite stubborn, if properly trained, they remain loyal and excellent guard dragons. They can swarm together in order to scare off either predators or villains away from the Dragon's Edge.
 * According to Rise of Berk, Night Terrors are extremely elusive. This may be because of their skittish tendencies and the fact that many a Viking could be scared off by them while thinking they were a larger dragon.
 * The Night Terror is the third black dragon to be seen in the franchise after the Night Fury and the Sword Stealer. Though they also appear dark green in Rise of Berk.
 * Night Terrors are very similar to Speed Stingers.
 * Both hunt in packs.
 * Both are led by a leader.
 * Only the lead dragon has a distinct appearance.
 * They are both nocturnal.
 * Both can move extremely quick.
 * The Red Death's roar was reused in one of the Night Terrors roar.