Gunmar

"To WOUND me, one needs to be able to touch me, child. Tell me, "Trollhunter", what should a father do to the one who MURDERED his only son?!"

- Gunmar to Jim about the latter killing Bular and attempts to kill him out of vengeance. "It can't be! It…can't!"

- Gunmar's last words as he turns to stone after being slash through body by the sword before Jim pushes him off the roof where he shatters to pieces.

Lord Gunmar is the main antagonist of Trollhunters, the first installment in the DreamWorks computer animated TV series trilogy, Tales of Arcadia (although the overarching antagonist in Part 1 and the central antagonist in Part 3). He is the ruthless leader of the Gumm-Gumms, an evil troll race who were sealed away along with him into the Darklands by Deya the Deliverer, and is Bular's father.

He is voiced by Clancy Brown, who also played Mr. Krabs in the SpongeBob SquarePants franchise, Lex Luthor in the DC Animated Universe, and Surtur in the 2017 Marvel movie Thor: Ragnarok.

Birth
Gunmar was born from the Heartstone of the Troll race. When the wars between humanity and Trolls were unleashed by the domination of the surface, the horrible killings and deaths of people corrupted the Heartstone, causing it to rot from within, and from inside it Gunmar was born. He also killed the King of the Quagawumps.

Conquest for Power
He fought against Orlagk for the right to be the leader of the Gumm-Gumms, a battle that ended Bronyak's death and the loss of his eye. After the Troll world and the human world are separated, Gunmar led his army to conquer the world and to destroy human race. This unleashed a war between the Gumm-Gumms and the rest of the Trolls that ended when the Trollhunter, Deya the Deliverer, defeated Gunmar, sealing him and all his army to the Darklands.

Part 1
Centuries later, his own son Bular teamed up with the Janus Organization to piece together the pieces of the Killahead Bridge under the guise of the Arcadia Museum, headed by the chief curator and fellow changelings Nomura, Otto Scaarbach, and Stricklander. The changelings and the Gumm-Gumms managed to open up the Bridge with the amulet that they had retrieved from Jim, and Bular briefly was able to speak to his father before contact was lost. The bridge was eventually destroyed by Draal, who removed the amulet before Gunmar could be unsealed from the Darklands.

Upon learning of the death of Bular, he sent Jim a message through Gnome Chompsky, who had been sent into the Darklands through a Fetch some time prior, threatening to murder everyone Jim had ever loved for killing Bular. In the threat, translated by Blinky from Gnome Chompsky, Gunmar promised an 'ocean of blood' for Jim and his loved ones, that he would 'create a throne from their bones'. After Angor Rot was killed, with AAAAAAAARGHH!! sacrifices himself to save Toby, Jim, clad in his new Eclipse Armor and Sword, goes into the Darklands to kill Gunmar himself, much to the horror of his friends.

Part 2
In Part 2, he makes his full appearance in the second episode, after his advisor Dictatious, brother of Blinky who was thought long-dead, introduces him to Jim, who was just captured by his Gumm-Gumms after barely making it through the portal back home. He noticed that one of his soldiers failed to defeat Jim, and used his Decimaar Blade to force him to commit suicide.

Immediately afterward, he noticed Jim is the new Trollhunter, and comments that Merlin chose a human child to be his Trollhunter. While Dictatious warned him not to be too careless, as he wields the Eclipse Sword, Gunmar asked if he can wield it. When Jim tried to slash him, he merely dodges his attack and states that to wound him, one needs to be able to touch him first. He then headbutted Jim to a wall, and angrily asks him "What should a father do to the one who MURDERED his only son?!", and then tried to smash his skull in with his fist. However, much to his (and Dictatious's) shock, Jim's armor created a helmet for one of the Triumbric Stones and saved him from death.

However, still outraged, he attempts to punch the helmet off him, up until the helmet fazes out and exposes him. Just as Gunmar was finally able to kill him, Dictatious, after noticing a piece of candy that was sent to the Darklands through a fetch by Toby, tells him to stop and let him live, much to his dismay. He then had Jim taken back to his cell, with the Gumm-Gumms dragging a vengeful Jim back.

After Dictatious commented that he showed restraint, Gunmar angrily asked him why would he prevent him from killing Jim. He then states that the Bridge is gone, and that he isn't willing to let the resulting dying world take him with it. Dictatious then answered that he offers a morsel of hope for him, giving him the candy he found and telling him that his friends are sending him coded message.

Gunmar then correctly realizes that his friends are looking for him, and that the bridge may still be open, but he would get this chance with Jim alive. He then states that the trolls thought they could stop him by trapping him in the Darklands, but it instead only hardened him, and vows that when he brings the entire world into total darkness and that trolls will reclaim the world as their own, under his rule. He later escapes the Darklands with Dictatious, a few Gumm-Gumms, and some Blood Goblins.

Eventually, Gunmar goes face-to-face with Draal, who gains the upper hand at first. However, Gunmar soon overpowers Draal, and brainwashes him to do his bidding. He uses Draal as his vessel while Draal fights with Jim and his companions at Arcadia Oaks High (Jim's school), and speaks through Draal.

Gunmar eventually destroys the Janus Order and uses Otto Scarrbach as his vessel as well, with the latter disguised as Gunmar, which leads Jim and his companions to the Janus Order once again. "Gunmar" fights Jim and is struck by the Sword of Daylight. However, he discovers it's Otto Scarrbach who is brainwashed by the real Gunmar, shortly before Otto explodes to his death.

With the charismatic evil-doer Usurna's help, Gunmar is able to sneak into Trollmarket and quickly take control. However, Jim and his companions are able to rescue many Trolls from Gunmar's tyranny, partly because of his friend, Claire, who creates a huge portal using the Shadow Staff to teleport herself, Jim, Toby, and the trolls to safety. (However, because she used too much power, she is linked to the evil wizard Morgana, who wishes to be free of her own imprisonment.)

Now that Gunmar is in control of Trollmarket, he creates a massive army of Gumm-Gumms to help him take over the world, while Usurna adds her bodyguards as part of Gunmar's army.

Part 3
Gunmar, who is already the ruler of Trollmarket, still wishes to release the Eternal Night, so he goes to Morgana for help, which she does so, but she is simply using him as a pawn (which Gunmar doesn't know).

After the travel, Gunmar reveals he needs to take the Staff of Avalon so he can release Morgana so the two can bring about the Eternal Night.

Gunmar, Angor Rot, and a brainwashed Draal eventually travel to the Staff of Avalon's location in the cavern where Merlin's Tomb. However, Draal is freed from Gunmar's brainwashing because magic stops working inside the cavern, which also causes Gunmar's Decimaar Blade to disappear from his hand. Angor, remembering what Stricklander once said to him, uses Draal as his leash, with Gunmar saying Draal will not make it out of the cavern alive.

However, Jim takes the Staff of Avalon, but Gunmar and Angor arrive. Draal protects Jim from them, but at the cost of his own life (Gunmar slashes Draal with his horns, while Angor finishes him off by using his magic dagger to stab him and turn him into stone). With that, Gunmar succeeds at seizing the Staff, and leaves Angor to die.