The Skrill
Famous for it's unique ability to absorb and manipulate lightning, The Skrill is often considered an omen for violent weather. This elusive and aggressive dragon has been well observed and documented from a distance, however the species shares a grudge against humans due to enslavement in Drago's army.
The dragon has large wings and a spiked back and tail. The spikes on the Skrill's back and tail are said to be sharp enough to cut bare skin without effort, and it's an excellent flyer. It also appears to have gills-like organs on its neck. The Skrill possesses a crown of spikes on its head which nearly all are the same length except the center "Primary" one. The Skrill's crown can also be used to give it expression, as it is able to control them to be pulled back or forward to an extent. Its head slightly triangular with two forward facing eyes, and its tail has an array of spines. The proportion of its head, body, and wings are quite close to that of a Night Fury. The similarities with the Night Fury only strengthen in flight, as a Skrill's speed and acrobatics are enough to compete or even possibly exceed the Night Fury.
However, Skrills can be identified apart from Night Furies by a lack of forearms, needing to use claws on it's wings to walk in a similar manner to a Monstrous Nightmare. And even though the ability to manipulate lightning is exclusive to the Skrill, that didn't stop a common old lore rumor that it was a Night Fury that was able to breath lightning.
Skrills do not settle down in a certain habitat like most Dragons, rather Skrills wander, chasing ever shifting stormfronts and magnetic fields for the most potential lightning. Even so, Skrills are very "Territorial" and will aggressively face anything that gets to close for their liking. As for a Skrills actual diet, they have been observed consuming fish, deer, boar, and even a domesticated yak from time to time but seem to enjoy mutton and goat the most.
How a Skrill is actually able to manipulate lightning and electricity is mostly unknown outside of using magnetic fields as no one has been able to document a Skrill up close or find a deceased Skrill to dissect. The most promising theory suggests that the scales on the skrill's body are naturally conductive and able to absorb electricity and that the gill like slits on the Dragon's neck help reverse the effect, thus projecting it's stored lightning.
Unfortunately, the Skrill's destructive potential makes this dragon species a prize for Poachers and Dragon Slavers, well worth a king's ransom in good health. It has been confirmed that Drago Bludvist had multiple skrills enslaved in his army, submissive and ready to to anything the madman ordered them to. And even though those days are long past, the Skrill as a species refuses to forgive humanity in any form and as such will refuse any attempt to bond.
In Conclusion, the Skrill is a fascinating dragon able to manipulate the power of magnetism and electricity to make of for it's lack of fire and is on a constant search for the most potent source of lightning, and thus drawn to violent storms. And while the Dragon's' abilities paved the road in the research and discovery of using electricity, abuse and enslavement by humankind has convinced them that all humans are the enemy. Do not approach, as a Skrill will not hesitate at all before going in for the kill.