Shattermaster

Shattermaster is a Gronckle who was ridden by Dagur in Dragons: Race to the Edge. Dagur was hoping for a Skrill or a Night Fury, but was a bit displeased upon seeing that he'd be riding a Gronckle. In fact, he initially thought that Shattermaster was going to be breakfast for a more powerful dragon. However, he completely changed his mind upon seeing Shattermaster's abilities.

Personality
Shattermaster is shown to be hyper-energetic and a truly friendly dragon. Much like Gustav and Fanghook before them, Shattermaster formed a strong bond with Dagur after only a day of training with him. He's also shown to be quite protective of Dagur, as seen when Astrid threatened to harm his rider if he betrayed them. Shattermaster doesn't even hesitate risking his life alongside his rider to protect the Dragon Riders and Heather.

Abilities and Skills
Munch like Fanghook, he proven to be quite Trail as fast under short day to be given great bond.

Intelligence: In one day, Shattermaster was able to have been trained quite fast, even with a trainer as inexperienced as Dagur. He was able to help his owner by using the chain to make the dragon hunter to trip over it easily.

Strength and Combat: He has proven to be very strong and fights like a typical Gronckle. He's even strong enough to briefly incapacitate Windshear with a tail bludgeon to the stomach.

Speed and Agility: Shattermaster has been proven to be quite fast for a typical Gronckle. He is even shown to be agile enough to dodge Windshear's attacks and was able to do a back flip to dodge a barrage of the Dragon Hunters' arrows.

Inverted Gronckle Drop: Inspired by nearly falling out of the sky on his first flight with Dagur, Shattermaster was able to master a modified version of Fishlegs and Meatlug's Gronckle Drop. It's an effective yet borderline insane maneuver, not unlike Shattermaster's rider.

Endurance and Stamina: He proven to take a large boulder that attack him as it took him down to be unable to fly but still able walk thanks to the support of his owner to find safe spot. His stamina is good as any other Gronckle.

Appearances
Family on the Edge (debut)

Family on the Edge
Shattermaster first appeared as Dagur's new dragon. He was chosen by Hiccup, mainly because he thought it would be safer for Dagur to ride the "slowest and least dangerous dragon" he could find. At first, Dagur refused to train Shattermaster, claiming he was "beneath him". However, Dagur accepted him soon after his failed attempt to mount him. The duo then enthusiastically began training with Hiccup, and later Fishlegs. Shattermaster was said to be a fast learner, as shown by his mastery of the Inverted Gronckle Drop. When Dagur was locked up after being accused of spying for the hunters, Shattermaster broke them out, which prompted Fishlegs to comment on how well they had bonded. Upon reaching the hidden shipyard, Dagur and Shattermaster charged into battle and laid waste to the hunters' fleet. Unfortunately, Shattermaster and Dagur were shown to have not survived and were presumed dead.

Trivia

 * No Gronckle has the same coloration as Shattermaster.
 * It is possible that Hiccup trained Shattermaster before giving him to Dagur, due to his behavior towards humans. As their was sign that he was able to call upon Shatter sister by using a whistle.