Eruptodon

The Eruptodon is a large Boulder Class dragon which appears in School of Dragons and in Dragons: Race to the Edge, Season 4.

Description
"Revered as a "great protector", the Eruptodon eats the lava from inside Caldera Cay's volcano to defend the Defenders of the Wing. With its craggy igneous hide, heat-shielded eyes, and endless appetite for magma, the Eruptodon prefers to live inside volcanoes to be nearer to its food source. This natural give and take between Geology and dragon protects the Defenders of the Wing from catastrophe, and as a result, the warrior tribe worships their loyal Eruptodon. Although not much of a fighter, the Eruptodon provides tremendous damage control by eating any runaway lava - even if it's regurgitated by Gronckles! The Eruptodon nests at the lips of dormant volcanoes and stops eruptions by consuming the lava. The Eruptodon's body is covered in thick, spikeless volcanic rock armor made of cooled lava. Its eyes are protected by welder goggle-type lenses to help withstand the intense heat. The Eruptodon is worshiped by the Defenders of the Wing because it saves their village by eating the lava from the active volcano on their island."

- Dragonpedia

"Though not a warrior, this dragon unleashes explosive violence when in dire straits. Nearly immune to heat damage, it is a vast force to be reckoned with."

- Dragons: Rise of Berk

Hatchling to Adult
Eruptodons are large dragons that have a round body and quite a long tail. Their wings are quite large and their heads are as big as their bodies. Their front legs are very small compared to their hind legs and they have several big, spiky lobes along their backs and tails. Its body is covered with thick spineless, volcanic rock armor made of cooled lava. Its eyes are protected by welder goggle-type lenses to help withstand the intense heat.

Behavior and Personality
The Eruptodon is the first known dragon species to eat lava. It prevents volcanic eruptions by residing in the magma vent of a volcano and eating overflowing lava. As such, Mala and her people worship this dragon for protecting their village. She mentions that the Eruptodon never allows the lava to flow too far down, hinting that the dragon may have a protective streak over the whole island. It is not actually just a passive protector, however, as it actively rescues Throk when he is trapped in the lava with Hiccup's bathysphere.

If an Eruptodon has not eaten for a long period of time, it will go into a feeding frenzy and will eat any lava it can find. If it can not find any, it will die. It does not require an active volcano to eat, as, if sufficiently motivated, it will tunnel into dormant volcanos to access the lava, causing them to erupt in the process. Nothing, except lava in another direction, will stop them once they are in a feeding frenzy.

Lava-Proof Skin
Due to its lava-proof hide, the Eruptodon can live inside a volcano without being harmed.

Heat-Shielding Eyes
The eyes of the Eruptodon are surrounded by rocky armor, protecting them from being burned in its volcano home.

Strength
The Eruptodon has been shown to be very strong, as the Great Protector was capable of lifting the heavy metal Diving Bell as well as the weight of Throk inside of it.

Heat-Resistant Saliva
The saliva of an Eruptodon is extremely resistant to heat. This saliva can be used to protect people who are trying to enter a volcano like the one on Caldera Cay.

Firepower
The Eruptodon's fire comes from the lava that it eats. It fires this lava in a series of molten fireballs. These fireballs can can cool down into hot rocks and can even construct a path that can be walked upon, albeit painfully, as seen in Saving Shattermaster.

Digging
The Eruptodon is capable of digging into the crust of a dormant volcano in order to access the lava within.

Lava Eating
The Eruptodon's main food source is lava. Because of this, it is able to stop volcanic eruptions by eating the lava and keeping the volcano stable. Even baby Eruptodons have been shown to be capable of doing this. It is due to this ability that the Eruptodon is worshiped by the Defenders of the Wing.

Weaknesses
If an Eruptodon does not consume lava for a long period of time, it will die. After having gone for a few days without eating on Viggo's ship, the Eruptodon became desperate and tried to attack a dormant volcano in a frenzy.

The Eruptodon only produces one egg during its lifetime. This could cripple the species, as it would make their population very small. It probably reproduces asexually, as it is a very rare and rather sedentary dragon. In addition to this, the Eruptodon on Caldera Cay is referred to as male until laying its egg and is referred to as female after. If the egg of an Eruptodon is not immersed in lava like the kind inside the volcano on Caldera Cay, it will harden until it is like stone and the baby inside will die.

Dragons: Race to the Edge, Season 3
First mentioned in "Defenders of the Wing, Part 1", the only Eruptodon known to exist was found on Caldera Cay, an island ruled by Queen Mala of the Defenders of the Wing. It was known as the Great Protector. However, it was taken by the Dragon Hunters when Mala was interrogating Hiccup and his group.

Dragons: Race to the Edge, Season 4
In "Defenders of the Wing, Part 2", the Great Protector (a female Eruptodon) was captured by Viggo and Ryker. She was aggressive at first, then became more interested in her own survival. Mala is worried about the Eruptodon, and said that Eruptodons must constantly eat lava, or they will starve to death. But Viggo plans to use the dragon to destroy Dragon's Edge by having her feed on the lava of the Edge's dormant volcano to cause an eruption. However, Mala and the riders arrived in time to stop her before she could produce a volcanic eruption by feeding her with Gronckle lava and get her back to Caldera Cay.

School of Dragons
The dragon made its first physical appearance in this game, during Return to Dragon Island expansion pack.

Dragons: Rise of Berk
The Eruptodon will appear in this game as Magmadon was released.

Trivia

 * It is the first dragon (not created in a video game) which makes its first physical appearance in a game before it does in the show.
 * It is the second dragon with lava-proof skin, the first being the Red Death.
 * It is the second dragon that is seen as a statue before being physically seen, the first one being the Grapple Grounder.
 * The Eruptodon is very phoenix-like because of the way it lives for generations then lays a single egg before it dies.
 * This and the Dragon Hunters would be the top contributors to making it an endangered species.
 * It is similar to the Fire Dragon from the book How to Twist a Dragon's Tale, as it is a giant, volcano-dwelling dragon whose egg can only hatch once it is immersed in lava.
 * It's very likely that when the Eruptodon fires its balls of lava, the lava mixes with the Eruptodon's heat-resistant saliva, which can be the reason why its lava blasts can be cooled down to form hot rocks very quickly.
 * The Eruptodon is the fourth dragon to have an individual appear in Dragons: Rise of Berk before the species itself did (Magmadon).
 * The first dragon was the Catastrophic Quaken (Spikeback), the second was the Gobsucker (Muddlehunt), and the third was the Triple Stryke (Sleuther).