Navarog was a huge black dragon who was widely acknowledged as one of the most corrupt and dangerous of all dragons. Recognized as a prince among demons for he was the son of Velrog the first of the demonic dragons, he sold his honor long ago in exchange for power. An armor of dark, oily scales covered his sides and back, and his belly appeared encrusted with black jewels. Cruel spikes protruded from his massive tail and along his spine, his claws carved like huge scythes, and his eyes burned like magma. Bigger than most dragons, Navarog had two long horns atop his skull.
He could maneuver in harsh weather better than most other dragons and one of his breath weapons could fire molten gold. He also had the ability, like most dragons, to take human shape when he so chose, where he was known as Gavin Rose.
In his human form, specifically, when he went by the name Gavin Rose, he outwardly seemed like a sweet, brave sixteen-year-old boy with a stutter, though he later admitted to Kendra that the stutter was a faked effort to seem more endearing. His avatar had flawless skin and dark hair, and he was rather good-looking.
Navarog was captured and put into the Quiet Box at Fablehaven. It is unknown how he got captured, as well as whether he was considered one of the twenty lost dragons, as he was never formally admitted to a dragon sanctuary.
Navarog, disguised and imprisoned, was led out of the Quiet Box by the Sphinx and released onto Fablehaven property. He used a spell to summon the Revenant's nail, recently removed by Seth Sorenson, and gave it to Kurisock. He left the property that same day.
The dragon also killed Chuck Rose and took on a new identity as his nonexistent son, Gavin Rose. Navarog pretended to be a Dragon Brother with a bad stuttering problem. He was proven trustworthy, became a Knight of the Dawn and went on several missions.
Navarog, in the form of Gavin, went to the Lost Mesa preserve to recover one of the secret artifacts with Warren, Dougan, and Kendra. He helped them past Chalize, the dragon who was guarding the vault where the secret artifact was supposed to be hidden. Navarog later killed and framed Javier for attempting to steal the decoy artifact.
Navarog, or Gavin, went on a mission to Wyrmroost with Kendra, Seth, Tanu, Warren, Mara, Trask, and Dougan to recover the key to the Obsidian Waste vault. After entering the Dragon Temple, Gavin killed the guardian Hespera alone in his dragon shape, turned back into Gavin and rejoined the others.
Later on in the book, while surrounded by dragons, Gavin transformed into his true dragon form, ate Dougan, and knocked Mara off a cliff while Kendra watched, frozen by the strong magical fear he exuded. After Kendra managed to run away into Sidestep Cleft, Navarog killed the dragons assailing him.
A short time later, Navarog turned back into Gavin and confronted Kendra inside Sidestep Cleft, with Nafia standing guard. He burned the magical knapsack, trapping an injured Warren inside. However, Navarog and Nafia were unaware that Raxtus had flown invisibly into the cave behind him. Not knowing of Raxtus' presence and unable to transform into his dragon form, Raxtus ate him.