Skullcrusher

Skullcrusher is Stoick the Vast's Rumblehorn before becoming Eret's who first appeared in How to Train Your Dragon 2.

Official Description
"From the Rumblehorn species, Skullcrusher is part of a previously undiscovered class — Tracker Class, being that he is the bloodhound of the dragons. He can find anything on scent, like when he found Hiccup in Valka's nest based only on Hiccup's lost helmet. Skullcrusher looks like a truffle pig mixed with a rhino, but much bigger. He has chitinous green-red iridescent coloring and surfacing of a scarab beetle and keeps his battle axe-shaped muzzle in the dirt, sniffing things out."

- Dragonpedia

"This walking battering ram may have a sensitive nose, but he has a very hard head. Maybe that's why he and Stoick get along so well."

- Dragons: Rise of Berk

Meeting Stoick
"Well, you're magnificent! And you've got a lot to say, don't you? Now, let's see if you can back it up."

- Stoick

As shown in "Crushing It", Skullcrusher was the first Rumblehorn found by Berk's Dragon Riders on Dragon's Edge. They believed that he was trying to destroy the Edge and drive them out when in reality he was attempting to warn the Riders of an incoming tidal wave. They spent some time trying to catch and relocate him until Stoick came to help and realized that he wasn't interested in destruction. Together with Stoick and the Riders, they were able to save the outpost from being wiped out, with the Rumblehorn proving particularly useful in completing the stone wall that had once been erected to keep him out. Stoick then named him Skullcrusher — on account of their mutual hard heads — and took him to Berk with him. He was also given Thornado's saddle, which was later upgraded by Stoick.

Being Stoick's New Steed
"Don't worry boy, this should only take a minute."

- Stoick

In "Team Astrid", as Stoick's dragon, he defended Berk when Dagur the Deranged attacked. Skullcrusher then went with Stoick, Astrid, and Stormfly to aid Hiccup in defending Dragon's Edge. He and Stoick charged through a Berserker ship and sunk it, but got caught in one of the ship's nets in doing so. However, Stoick was able to free him and he then fought alongside the Dragon Riders' Auxiliary, driving Dagur away.

Later, in "A Time to Skrill", Skullcrusher also aided Stoick and the Dragon Riders' Auxiliary in defending Berk from the Frozen Skrill that was seeking revenge on Hiccup and Toothless.

Continuing as Stoick's Dragon
During the events of "Turn and Burn", Skullcrusher then assisted Stoick in tracking down Spitelout when he went missing for a month. Together, along with Hiccup, Snotlout, and their dragons, they found him and Kingstail on Storehouse Island. However, they came under attack by the Singetail. They were unable to drive it away and were forced to give up the island when other Singetails arrived. Before leaving, Skullcrusher and Stoick took the "S" from the storehouse.

When Hiccup talks to Stoick about how Viggo Grimborn will come after Berk's dragons in "Last Auction Heroes", Stoick looks at a sleeping Skullcrusher and agrees with Hiccup's plan. Skullcrusher is then seen playing with Toothless at the Academy.

The Attack on the Dragon Hunters
In "Shell Shocked, Part 1", Stoick and Skullcrusher take part in Hiccup's mission to retrieve the Dragon Eye from Viggo. However, when they arrive at the Hunters' base, they find it devastated. Skullcrusher then returns to Berk with Stoick.

Skirmish with the Dragon Flyers
"Come on, big boy. We're not going down like this. That's a good fella!"

- Stoick

When Krogan's forces temporarily overtook Dragon's Edge in "The Wings of War, Part 2", Stoick and Skullcrusher led an attempt to reclaim it. The Rumblehorn and his rider fought an arduous battle against the Dragon Flyers, though the tide turned in their favor when Hiccup, Spitelout Jorgenson and Gustav Larson enact a plan to have the Singetails abandon their Flyers. Later on, Skullcrusher and Stoick accompanied Astrid and Stormfly in chasing down Krogan and Viggo, avoiding the barrage of fireballs created by Krogan's Singetail before being hit and thrown off course. Skullcrusher and Stoick manage to recover before making a safe landing.

Fighting the Final Battles Against the Dragon Hunters
"Skullcrusher, SOS!"

- Stoick

Stoick was outraged when he learned about Johann's true allegiance in "No Bark, All Bite", and Skullcrusher did not hesitate when the Hooligan chief commanded him to burn all of Johann's latest shipments. He later accompanied Stoick, Hiccup and Toothless in their search for willow bark, fighting off Dragon Flyers along the way. When Hiccup and Stoick's relationship became strained through their arguments, Skullcrusher and Toothless work together in having their riders forgive one another. The group soon fly back to Berk when they realize Johann's true plan, and Skullcrusher helped Stoick in confronting Krogan to give Hiccup and Toothless time to free the imprisoned dragons and retake Berk from the Hunters and Flyers.

In "Darkest Night", Stoick and Skullcrusher were out patrolling on their own when they got ambushed by Dragon Flyers. Skullcrusher successfully sent an S.O.S. to the other Dragon Riders before being incapacitated by the Singetails' fireballs. Despite his condition, Skullcrusher managed to rescue his rider from certain death and was carried back to Berk by Grump to make a complete recovery.

War with Drago's Army
When Hiccup went with Toothless to try and reason with Drago Bludvist, Skullcrusher helped Stoick, Gobber, and Grump to track down Hiccup, using the latter's lost helmet. They were able to find Hiccup and encountered Stoick's wife, Valka, at her mountain. He, along with Stoick, Hiccup, Gobber, Valka, and their dragons then defended the mountains against Drago's army. However, after Drago's Bewilderbeast killed Valka's, the former took control over all the dragons, including Skullcrusher.

At Berk, after Drago and his Bewilderbeast are defeated, Skullcrusher and all the other dragons bow down to Toothless, their new Alpha. Following Stoick's death, Hiccup suggests that Skullcrusher passes into the care of their new ally and former dragon trapper Eret, Son of Eret, recognizing Eret's skill and courage in helping Berk defeat Drago Bludvist. After this, he and Eret then took part in Berk's Dragon Races.

Being Eret's New Steed
Skullcrusher is seen being ridden by Eret, on the way to Nepenthe. The latter has difficulties in controlling the dragon and Valka advises him to give the Rumblehorn a gentle touch.

On the island, unlike the other dragons, Skullcrusher isn't attracted to the hot pools, but he still doesn't find anything out of the ordinary, that could lead to the cause of the tremors.

At dinner, after Calder reveals his true nature, Skullcrusher prepares himself to fight. However, due to being outnumbered, he and the riders surrender.

After Hiccup escapes, he frees all the dragons, including Skullcrusher, and everyone prepares to leave the island. However, right at that moment, few Foreverwings wake up and begin destroying the village. Although Skullcrusher does not appear while the riders help the people of Nepenthe, after Hiccup defeats Calder, he carries Eret to the scene, to see what happened. He then returns to Berk.

Physical Appearance
Skullcrusher is a full-grown Rumblehorn with green and orange scales, a red face, as well as a light underbelly.

Personality
"Doggedly determined when he's caught a scent."

- Dragonpedia

In comparison to Grump, Skullcrusher is stern and serious looking, and sometimes a little stubborn — corresponding with the personality of Stoick. He always has his nose to the ground, following a scent, as is typical for his species.

Skullcrusher can be friendly, especially towards his rider. He is doggedly determined once he has caught a scent. He is caring and a natural leader, warning the other dragons of an oncoming tsunami to ensure their safety.

Skullcrusher also has a playful side, like spinning around while flying. He was also seen playing a bit with Toothless in "Last Auction Heroes".

Abilities and Skills

 * Tracking: Like all Rumblehorns, Skullcrusher has a keen sense of smell, enabling him to track anything once he has caught the scent.
 * Strength: Rumblehorn raming into a sea stack.gif]] Skullcrusher possesses an incredible level of strength. He can charge with his head lowered and horns displayed to do some serious damages. He also doesn't have trouble carrying large Vikings on his back such as Stoick and extra weight of Hiccup. Skullcrusher's extreme strength was greatly proven when he was able to ram down a sea stack when flying at full speed towards it, as well as during the time when he charged clear through a Berserker ship and sunk it into the ocean.
 * Endurance: Skullcrusher is able to recover rather quickly after being directly hit by a Singetail's fireball.
 * Fire: Skullcrusher can shoot burning, explosive missiles from his mouth that can do a lot of damage.
 * Acrobatics: Skullcrusher has some impressive agility in the air despite his large size.
 * Speed: Skullcrusher is also surprisingly quick on his feet and in the air.
 * Intelligence: Skullcrusher has shown to be able to try to figure out ways to make other dragons to flee the island before they could be killed.

Stoick the Vast
Stoick first met Skullcrusher on Dragon's Edge, and the Rumblehorn was initially perceived by the Dragon Riders as highly aggressive. After their first encounter, Stoick realized that Skullcrusher was trying to warn everyone about a massive tidal wave that is coming to wipe out the island. Stoick and Skullcrusher worked together in saving the Edge and formed a strong bond in the process.

Skullcrusher and Stoick continued to fight together as the threat of the Dragon Hunters and the Dragon Flyers arose. When Stoick got nearly killed by a Singetail's fireball, Skullcrusher swiftly lifted him to safety until the Dragon Riders' Auxiliary came to their rescue.

When news of Drago Bludvist's campaign reach Berk, Skullcrusher aided Stoick by tracking down Hiccup after he flew off on his own. The Rumblehorn later helped his Rider again in rescuing Valka after she nearly fell to her death.

Eret, Son of Eret
Skullcrusher first met Eret when the Dragon Riders came to rescue Hiccup and Astrid, but they didn't really interact with one another. After Stoick's death and Drago's defeat, Skullcrusher approaches Eret and nudges the ex-trapper in a friendly manner. Eret was honored to have the Rumblehorn as his dragon, and the two immediately became close friends.

Toothless
Toothless initially disliked Skullcrusher due the latter's first impression as a rampaging wild dragon on the Edge. It was eventually revealed that the Rumblehorn was trying to warn everyone about a gigantic tidal wave, and the two dragons worked together in saving the Edge from being destroyed. Skullcrusher and Toothless became friendlier to each other, as they are sometimes seen playing together.

In How to Train Your Dragon 2, Skullcrusher acknowledged Toothless as the new Alpha Dragon by bowing down to him.

Trivia

 * An image error in Empire Magazine led to believe that the Thornridge was a new dragon species with the same name. The description and combination of animals were indeed about the Rumblehorn.
 * Along with Thornado, Skullcrusher is the first dragon whose former rider is deceased.
 * Skullcrusher is the first dragon who had more than one rider, excluding Barf and Belch.