Kelger is an anthropomorphic lupine, appearing closely to a typical depiction of a werewolf. In his official artwork and portrait by Yoshitaka Amano, his fur is in shades of grey, but his in-game sprite depicts him as having fur in a light shade of brown. He wears a gold headpiece with a protruding horn behind his ears. He wears a full-body armor and a yellow cape.
Kelger is initially distrustful of Bartz, Lenna, and Faris, and asks Bartz to mettle with him to prove his worth. Kelger is loyal to his friends however, and when he learns Bartz is the son of his old acquaintance, he accepts the party with open arms.
Kelger a Warrior of Dawn along with Galuf, Dorgann, and Xezat. The Dawn Warriors sealed the supernatural warlock Exdeath in a cave thirty years ago. He is a werewolf and, like all of his race, hails from the town of Quelb, where he is leader. Galuf, along with Bartz, Lenna, and Faris, visit the town and Kelger challenges Bartz to a fight, believing him to work for Exdeath, who has now been freed.
Kelger initiates his "Lupine Attack" (known as Pine Attack in the Anthology translations), but is defeated by a powerful blow that sends him through a door. While recovering, Kelger learns Bartz is Dorgann's son, and the party's real motives for coming to Quelb, and grants them passage to Drakenvale to the north. Later, when the party is in Castle Exdeath, already weak and dying, Kelger sacrifices his life energy so the party can see through the illusion spell cast up by Exdeath. He is the last of the Warriors of Dawn to die.
A Lupin resembling Kelger, currently just referred to as "Lupin Youth," appears alongside the game's version of Galuf and two others resembling the Dawn Warriors.
- Clearing Kelger's Lupine Attack challenge earns the player the "Lupine Attack" achievement.
- In the GBA/PSP/iOS remakes of the original Final Fantasy, Kelga is one of the automatic names the player can choose for the Thief job.
- Although Kelger Vlondett was a non-playable character, he can be considered the first hero of the "beast" archetype in the Final Fantasy series. This archetype would be repeated again with future characters Umaro, Red XIII, Freya, Kimahri, and Fran.
- Kelger, along with the other Dawn Warriors, has a trophy/achievement named after him in Final Fantasy XIII, "Kelger's Cup".