Jim Lake Jr. (current)
Jim was the first human Trollhunter, but never was meant to stay that way. To defeat Gunmar, Merlin turned Jim into a half-troll to give him a fair chance of defeating him.
He was the last Trollhunter before Jim was chosen. He was killed by sunlight to keep Bular from getting the amulet.
Deya was the great Trollhunter that trapped Gunmar and the Gumm-Gumms in the Darklands. In 1620, while on the docks of the Mayflower, before they set foot on the ship, Bular came rushing at Deya with his swords. Deya told the trolls to get onto the ship while she went to fight Bular, Draal tried to help Deya but Kanjigar stopped Draal and told him that Deya has given them the chance to escape Bular. The Mayflower set sail with the Trolls and a few Gnomes hid in the ship, Vendel and Blinky hope they done the right thing by leaving Deya behind. Bular and Deya tumble off the dock and into the water where they fight until Bular blinds Deya with sunlight reflected off his sword, the amulet somehow gave Deya sight but the sun came up and turned Deya to stone and Bular ran to keep himself from turning to stone.
Unkar was the Trollhunter for six hours, on his first and only night, he battled Gumm-Gumms on the stairs of a temple, while fighting he was shouting some very egocentric things liked how he always wanted to wear the armor. When Inkar reached the top of the temple, he tripped and felled into a hole of spikes. Bular pulled his body from the spikes and discovered that he was still alive then he ripped Unkar limp from limp.
Draal, "The Deadly" (alternate reality)
In an alternate reality, where Jim was never chosen to be the next Trollhunter, Draal inherited the amulet from his father when he fell during his battle with Bular.
Before Kanjigar, even before the Days of Gogun, Trollkind was protected by one of its most celebrated heroes. Maddrux cultivated a reputation as a capable and confident champion. Her story was farther expanded up in the graphic novel Tales of Arcadia--The Felled. She battled Orlagk the Oppressor with his clones, but he escaped that day.
Araknak was one of Blinky's relatives. He had overprotective parents who watched him fight a pair of gruesomes while they were staking him during one of his Trollhunts. He chose to pursue the path of a warrior not of an academic like his parents.
Spar was the very first Troll to meet an Akiridion, he helped the visitor get back her planet by pushing her ship off the edge of a cliff to gain velocity and leave the planet. This brief encounter with an alien taught him how to bring balance his own, it also gained him the respect of the humans and learned to respect the primitive cave people.