Fangtom is the Serpentine General of the Fangpyre tribe. He was previously friends with Skales before being sealed away initially. He has two heads, which take turns talking and finishing his sentences—the left head speaks with a high voice, and the right head speaks with a deep voice.
At an unknown point in time, Fangtom became the leader of the Fangpyre tribe, likewise appointing his brother Fangdam as his second-in-command. Later on, presumably in combat, Fangtom accidentally bit himself, his own venom horribly mutating him, giving him an additional head.
Later on, he would lead an attack on the humans alongside his Serpentine brethren, only for the five tribes to split apart, declaring war on each other. He was eventually subdued by the Sacred Flutes and imprisoned with the rest of his tribe within the Fangpyre tomb.
Fangtom and his tribe were freed from the Fangpyre Tomb by Lloyd Garmadon, who explained that he was seeking vengeance on the Hypnobrai tribe after they betrayed him. Fangtom agreed to the plan, but mentioned that his tribe was few in numbers and that they would need reinforcements. Fangtom and his army then went to Ed & Edna's Scrap N Junk, turning the items of the junkyard into Fangpyre vehicles as Ed and Edna watched in horror. The General revealed his intentions of building an army before his forces bit Ed and Edna as well.
When the Ninja arrived the next morning, Fangtom oversaw his tribe's attack against them. When the battle turned in the Ninja's favor, Lloyd called a retreat, with Fangtom joining him on the platform of a Rattlecopter. The Ninja gave chase in their new vehicles, and Jay managed to snatch the Fangpyre Staff out of Fangtom's hands. The General immediately ordered the rest of his forces to attack and reclaim his staff, but the Ninja fled aboard the Destiny's Bounty.
Fortunately for Fangtom, Nya accidentally dropped the staff out the back of the ship, where it bounced off of a soldier's head. As Fangtom retrieved his staff, he snarled that the Ninja had to be stopped, and a dust-choked Lloyd weakly agreed.
Never Trust a SnakeEdit
Despite their recent defeat, the Fangpyre had successfully built up their forces enough to helped Lloyd attack the Hypnobrai. Fangtom sat atop the Fangpyre Wrecking Ball as his tribe rolled into the Frozen Wasteland, but called off his attack when he saw Skales leading the Hypnobrai. The two Generals welcomed each other's company, revealing that they had been great friends before being sealed away, and Skales expressed relief that Fangtom's tribe had been released instead of the others.
As Lloyd spluttered in fury and shock, Fangtom asked Skales what they should do with Lloyd, asking if Skales could hypnotize the would-be evil overlord, making him act like a pig. After Skales shot down that suggestion on the grounds of Lloyd being useless as a fighter, Fangtom decided to turn Lloyd into a snake with his bite. When the Serpentine turned back to the wrecking ball, however, Lloyd was nowhere to be seen, having fled when he realized that the Fangpyre had betrayed him.
Can of WormsEdit
Fangtom, along with the other Serpentine Generals, were summoned to a meeting of the four tribes by Pythor.
The Snake KingEdit
Fangtom was summoned to the newly-uncovered City of Ouroboros by Pythor, along with the rest of the Serpentine. Once there, Fangtom found himself and his fellow Generals challenged to a Slither Pit by Pythor, with the stipulation that the Serpentine would submit to the latter's leadership if he successfully defeated the other four Generals simultaneously. Fangtom suffered a tail whip to the head early on, but managed to help Acidicus and Skalidor pin Pythor down.
Consequently, the three Generals missed Skales handing the Sacred Flute to Pythor, who used it to leave the other Serpentine leaders immobile with pain. With his opponents thus incapacitated, Pythor easily defeated the Generals, with Fangtom getting punched in both heads as Pythor snatched away his staff. With the staffs in his possession, Pythor declared himself to be the supreme master of the Serpentine, and Fangtom joined the others in bowing before the new Snake King.
All of NothingEdit
In order to prevent the Ninja from interfering in the search for the final Fangblade, the Serpentine dug a complex network of tunnels between the five tombs, with the Constrictai Tomb being enlarged into a massive underground fortress. While Pythor searched for the Fangblade, Fangtom remained in the fortress—along with his fellow Generals and most of the other Serpentine—in order to protect the three Fangblades they had already collected.
When the Ninja infiltrated the fortress to try and steal the three collected Fangblades, Fangtom was discussing the legend of the Great Devourer with Acidicus and Skalidor. He wondered if the beast would really consume everything once unleashed, but the discussion was interrupted by Skales's reminder to stay alert for Pythor's return. When the Ninja were spotted, Fangtom slithered into battle, only to find that Jay's metal armor was too tough for his fangs to pierce. Luckily, a cage trap at the base of the fortress caught the Ninja before they could grab the Fangblades.
Day of the Great DevourerEdit
After The Great Devourer was released, the Serpentine were forced back underground into the tombs to avoid being eaten. Fangtom blamed Skales for the release of the Great Devourer telling him that he (being Pythor's second-in-command) should have known Pythor's plan was terrible. Scales simply said: "How was I supposed to know he was mad!" When Skales jumped into the hatch to the tomb, he called Fangtom a coward, which made Fangtom call Skales a coward in return.
Pirates Vs. NinjaEdit
Fangtom and the other remaining generals soon joined up with Lord Garmadon who presented them with his new Mega Weapon, though the fangpyre doubted that Garmadon knew how to use the weapon. Garmadon eventually did figure out how to used it and inadvertently brought Captain Soto's crew back, who in turn took over the ship and threw Fangtom and the other serpentine into the brig. After the Ninja dealt with the Pirates, the Serpentine reclaimed the ship and Fangtom stood by Garmadon as he mocked the Ninja.
The Curse of the Golden MasterEdit
Fangtom is briefly seen among various other Serpentine inside the Stone Army's former tomb. Presumably, he has abandoned his evil ways like the rest of the Serpentine.