Dagur the Deranged

Dagur the Deranged is chief of the Berserker Tribe and sworn enemy of Hiccup. His ultimate goal is to take Toothless for himself, both to be his own personal pet and as vengance against Hiccup for tricking him. He does not appear in the original movie, but rather the spinoff TV Show DreamWorks Dragons instead.

Physical Appearance
Dagur wears the armor and weaponry of a chief. All green from head to toes, with straps, spikes and leather covering him. Metal covers his shoulders and knees, with his left arm covered up to his wrist, his right arm only sporting straps for maneuverability with his weapons. He is usually seen with a broadsword strapped to his back. He wears a large copper-gate viking helmet rimmed with spikes, his red braid let out the back, and two crooked horns jutting over a foot above him. He has a hooked nose, green eyes and has three blue-streaks of war-paint across his left eye. His belt buckled is carved with the crest of the Berserker crest, the Skrill.

Personality
The title of "Dagur the Deranged" is actually quite fitting, as he is seen as violent and extremely unstable. At times he performs erratic acts without thought or reason, other than to shed blood and kill. He is especially eager to kill dragons and sees them as nothing more than targets for his sadistic sense of pleasure. It is shown that while Dagur prides himself as a dragon killer, he has little regard to the sport, having brought his entire armada to assist him on his hunt for Toothless.

Aside from being considered as certifiably insane, Dagur's has an overwhelming sense of pride. As a result, he can be reckless and can easily be lured into a situation that puts him at a disadvantage. One such example was Hiccup challenging Dagur to a one-on-one battle between them and their dragons, despite Dagur's overwhelming advantage in numbers.

Dagur seems to hold a particular hatred towards his father and predescessor, Oswald the Agreeable. It is implied that Dagur killed him or at least took the position of chief by force, claiming he "lost his taste for blood". He becomes bitter and irritabel whenever someone speaks highly of him (which is everyone) and hates it when people "smack their food", claiming that Oswald did this.

Powers and Abilities
Dagur is an accomplished fighter and has shown to be able to face Alvin the Treacherous, agile enough to hold his own, though he isn't above using unfair means in order to win. He's strong enough to pick up Hiccup easily with no sign of struggle and can force a Skrill to use its power by pulling hard enough to attack. He's clever enough to see through Hiccup's plan to have Astrid distract the Berserker guards to leave his invention to catch the Night Fury and knows that dragon root can make dragons go into an uncontrollable rage, using it as part of a bargaining chip for Toothless. In battle, he is not much when it comes to strategy, preferring to just charge forward at his enemy, using the Berserkers' ferocity and sheer brute force.

Weapons
He is always seen with a broadsword strapped to his back, but has also been seen hunting with a crossbow and carrying a shield with the Beserker crest painted across it.

Dagur temporarily had control over a wild Skrill, tugging at it with ropes that he would hold onto for it to fire. However, the Skrill had absolutely no loyalty towards him and left him behind after accidentally shocking him into unconsciousness.

Role in the Crossover
Much like in the show, Dagur serves as a central antagonist to the Big Four, using every tactic in his arsenal to battle his enemies and usurp any force that stands against him. Unlike Alvin however, fanfiction writers like to broaden Dagur's character, maybe even finding love or at least some kind of compromise with the Big Four as a road to redemption or some form of epiphany.

Hiccup Horrendous Haddock III
Hiccup and Dagur have known each other for a long time, usually meeting with their tribes' treaty signing. Dagur often acts like a pesky older brother, using Hiccup as a knife throwing target or trying to drown him. Hiccup describes him as a "lunatic kid" and was not happy to learn he was the new Beserker chief. Dagur confronted Hiccup about the Red Death and trained dragon rumors he heard about, only for Hiccup to deny them. The dragon trainers staged a dragon attack to save Barf and Belch, and the Beserkers retreated. Hiccup later met up with Dagur again on Dragon Island, happy to see Hiccup alive after the "attack" and kept going on about how he faced a Night Fury. Dagur then decides the two of them will hunt down the dragon together. He even starts calling Hiccup "brother," which he finds awkward. Dagur points out he and Hiccup are a lot alike: both are born leaders, sons of chiefs, and have fathers that had to be elimitated; the last one Hiccup quickly disagrees with. When Dagur learns that the truth about Berk's dragons, he feels betrayed and attacks Hiccup and Toothless. Hiccup beats Dagur, and he and he others head back to Berk, as they need to be ready when Dagur returns. After being defeated and telling the Beserker armada, Dagur tells them no one is to hurt Hiccup, except him, after he gets his dragon.

After losing the symbol of his people, the Skrill, to Hiccup and Toothless, Dagur's pride has taken a very severe hit and this has only made him even more determined to destroy Hiccup and his dragon.

Jack Frost
The odds of Dagur being able to see Jack may depend on the story. As a Viking who worships the Nordic pantheon, Dagur would most likely be able to see Jack Frost because of being familiar with the name of Jokul Frosti (Jack Frost's original Scandinavian name). Jack's sworn enemy, Pitch Black, would see the fear that Dagur imposes, picking at Dagur's insecurities towards his father to manipulate him as part of a plan against the Big Four. For whatever reason, Dagur's Modern AU counterparts are commonly made as a sworn enemy to Jack, both possessing bad-boy personas (Jack being a harmless mischief-maker while Dagur as a dangerous punk) clashing on many occasions, leading to a bitter, violent history.

Merida DunBroch
As one of the more violent tribes of the Archipeligo, DunBroch's history with the vikings would lead Dagur and his Berserker armada to the Highlands, hungry for war. Merida, intending on fighting back, becomes a prime target and opponent for Dagur.

Rapunzel Corona
Dagur (and most other vikings for that matter) represent everything that Gothel taught her to fear - ruffians with pointy teeth and nasty, cruel intentions for those ill-prepared for the world. With her fair appearence, Dagur would naturally do what he can (by force if necessary) to "claim her" as his own. Besides that, he would still find value in a princess to a kingdom as prosperous and wealthy as Corona.