Thunderdrum

The Thunder Drum is the name of a species of dragon. The Thunder Drum do have feet, despite some people that think that they do not have legs.The Thunder Drum relies mostly on its two sets of wings, one primary and one smaller set to the rear, used to get around and move through the water like a tornado. The Thunder Drum is capable delivering a sonic blast of pure dragon power. When a Thunder Drum hatches from its eggshell, it makes a sound so loud it rattles the sky.

According to the Dragon Manual, Thunder Drums are roughly the same size as adult Vikings, and are reclusive in nature, living in sea caves and dark tide pools. The name comes from its main mode of attack/defense. When startled, they can produce a strong concussive sound that can kill a man (or woman) at close range. When a Thunder Drum egg hatches, it produces a noise loud enough to "rattle the heavens." Like nearly all dragons in the Manual, they are classified "extremely dangerous, kill on sight." It is also said that gets its power from Thor himself.



Trivia
Thunder Drums seem to resemble Eagle Rays in shape and color. Like Spotted Eagle Rays, they are blue with white spots and "fly" through water with wings. They also seem to resemble the Giant Bee-Eaters from the books. In a Dragons Riders of Berk episode Stoick the Vast gets one as a pet. He names it Thornado.

In the film
The Thunder Drum appears when Hiccup is reading the Dragon Manual to find information on Night Furies. In Book of Dragons, it is classified as a Tidal Class Dragon.

Dragons: Riders of Berk
In episode 7 "How to Pick Your Dragon" Stoick finds a blue Thunder Drum, which he has Hiccup teach him to train. Later that episode, Stoick and Hiccup find the blue Thunder Drum with a violet Thunder Drum. Stoick eventually tames the blue Thunder Drum toward the end of the episode and now it is "his dragon".

-note: It is not known if the Blue Thunder Drum will be series regular or if the violet Thunder Drum will be part of the Academy until the next few episodes. However in a early draft of a unnamed episode we see Stoick riding a dragon, so that MAY be a yes to Thornado.

Dragons: Wild Skies
In Dragons: Wild Skies, Thunderdrum can be tamed. It lives in Wreckers Reef and it needs to be fed crabs to tame this beast. You will need 10 Gold and buy a Crab Net, then go to Wreckers Reef, then you choose the crabs. The Thunder Drum is a Tidal Class Dragon and it screeches instead of breathing fire. When you are riding it, its mouth is closed. When you press the space bar it will open its mouth and screech at the target. Other Vikings will say that you were as strong as Stoick after taming it.