The Gronckle is one of the toughest (and slowest) dragon in the dragon world, and more than lives up to its looks in the battlefield.
The Gronckle can be a slow, lazy, and cranky bulldog-like dragon; it has been known to fall asleep mid-flight, waking only when it plunges into the sea or crashes into a mountain.
Because of its tremendous weight and small wings, it would seem impossible for them to fly. However, because the wings of a Gronckle beat at a speed similar to that of hummingbirds' dragonflies', or bees' wings, it is possible for one to sustain flight. In fact, a Gronckle can fly backward, sideways and even hover in place. Its tail can be mistaken for the head if little attention is paid.
It is also prone to dragon acne. Because of its large stout body and clubbed tail, the Gronckle somewhat resembles an Ankylosaurus. They spend the majority of the day sleeping. It has huge jaws which it uses to hold food when carrying it to the dragon mound. It has a rather blunt nose horn and fairly stubby toe claws. Its legs are practically useless in battle, and due to its short tail it has a fairly small attack range.
The Gronckle can launch a devastating fire attack but is limited to six shots at a time. Both its fire attack and hovering flight pattern makes it a very dangerous dragon. It can simply hover slightly out of reach of the Vikings and then blast them with its powerful fire. Unlike the other dragons, the Gronckle can refill its so called shot limit fairly quickly. Most dragons use a flammable gas, but the Gronckle eats rocks and then melts them in its stomach. So as long as there are edible rocks in the area the Gronckle will be able to refill its shot limit.
One interesting fact about a Gronkle's stomach is that it is able to melt down any type of rock and metal like a forge. By mixing certain minerals and ores, it is able to create an alloy called Gronckle Iron, which can be shaped into weapons and instruments that are lighter and stronger than those made of pure iron. Meatlug was able to create a large amount of Gronckle Iron, though she is unable to do so again since no one knows exactly what she ate at the time. Other mixtures allow them be magnetized, create glass (sandstone alone), overheat. Also Gronkles are the only known dragons immune to the effects of Dragon Root. Gronkle's can move munch faster when running then flying in the air. They are very manouvereble in the air, being able to go backwards, sidewards and even hold still.
The official Website describes the Gronckle as follows: "One of the toughest Dragons in our world is the GRONCKLE. Gronckles have gigantic heads, short bodies, and round tails. Gronckles are lazy, and spend most of their time sleeping in communal heaps. They have been known to fall asleep while flying, waking only when they crash into the ocean or the side of a mountain. Gronckles have relatively small wings that beat as fast as a hummingbird's. They are slow in the air, but make up for this with their maneuverability. A Gronckle can fly backwards, sideways, and even hover. Gronckles attack from the air, where their primary weapon is most effective. Gronckles chew rocks, melting them in their bellies and firing them as balls of molten lava."
"With its bulbous shape, tiny wings and laid-back demeanor, the warthoggish Gronckle is proving to be a fan favorite." Says Sanders, “He is a series of round balls, including warts. He’s just lazy, cantankerous and grumpy, and that makes you like him even better. The critter is known to doze off even in mid-flight as he floats about like the Goodyear blimp. But there is no denying that his fire packs a lethal punch."
Also mentioned in Book of Dragons "A gronckle has five phases of growth, just like all other dragons." Only three phases have been confirmed: first being the egg, second being a hatchling, and fifth is titan wing class.
In the FilmEdit
The Gronckle is the first dragon that the students have to fight in the arena. It is used to teach them how to use the shield to block attacks and shown to have a six shot limit. One almost blasts Hiccup, but he is saved by Gobber the Belch. Hiccup learns from Toothless that dragons love garlic grass and uses this to calm down the same Gronckle in a later training session. The Gronkle is used to determine who will kill the Monstrous Nightmare and is seen subdued by Hiccup (presumably through scratching a particularly sensitive spot dragons have), earning him that right. Hiccup later gives the Gronkle to Fishlegs during the attack on the Red Death and during the battle, it hovers beside the evil dragon's head, allowing Fishlegs to distract the Red Death by banging on his shield. This also confuses the Gronkle and causes it to crash and flip upside-down, pinning Fishlegs who ends up being okay. The Gronckle and Fishlegs are nearly crushed by the Red Death's foot, but thanks to Snotlout's antics, it barley misses them and the Gronckle is later seen flying around the villiage as Fishlegs' pet dragon.
In the BookEdit
It is shown in the book that Dogsbreath the Duhbrain and Wartihog both have Gronckles in the Pirate Training Programme. Dogsbreath's is called Seaslug. Stoick the Vast also has a Gronckle called Newtsbreath.
Gronckle eggs are the smallest of all the species. They are very rough and have dark brown color. They also bounce around like jumping beans. In Gift of the Night Fury, they are shown to explode when they hatch. Although the eggs are supposed to be barely larger than a marble, Gift of the Night Fury showed Meatlug's eggs to be just a bit smaller than the average Viking head and snuggly fitting inside Viking helmets.
As mentioned before, Gronckles are lazy and sometimes cranky dragons. They fly slowly due to their small wings and bulky bodies. But their fire attacks are devastating. They can be sweet natured at times, especially towards their hatchlings or their riders. They are faster on the ground and if they need to move quickly, they prefer to run.