Although this article is based on canonical information, the actual name of this subject is pure conjecture.
This unnamed Titan Wing Monstrous Nightmare appears in the episode Total Nightmare in Dragons: Race to the Edge. He was trying to destroy the eggs that Girl Hookfang was rearing. He appears when Hookfang protects Girl Hookfang and her eggs from him. After a long fight, Hookfang defeated him.
Appearance and Personality
He is much bigger than an average Monstrous Nightmare as he has reached the titan wing growth stage making him 69 feet in length. He has spots instead of stripes and is vibrant red and purple. (since he is the only Titan Wing Monstrous Nightmare in the series so far it is unclear whether all Titan Wing Monstrous Nightmares have the same color scheme.)
He is shown to be very aggressive, fierce, stubborn compare to Hookfang and not a quitter until he gets defeated by his enemies.
Being a fully grown Monstrous Nightmare, this Titan Wing has shown for his kind that their abilities are enhanced.
Strength: He appears to be extremely strong as he is able to throw average Monstrous Nightmares with his head, with no signs of struggle, or by tail whipping them out of the air, where Toothless was seen to struggle a little when fighting a Monstrous Nightmare.
Endurable and Stamina: The Titan Wing Monstrous Nightmare shows great endurance by taking multiple attacks from his enemies; two plasma blasts from Toothless, shots from Barf and Belch, several Monstrous Nightmare attacks and crashing into objects. From the chasing, taking the attacks, and crashing into objects he has proven his stamina is great enough to continue to fly away fast enough from Hookfang. As likely reasonable the Hookfang Nemesis have fought Hookfang just before Snotlout have arrive to say goodbye forever to Hookfang as Hookfang shown to be out of breath as he was lying on the ground.
Speed: This dragon has been shown to be able to fly very fast enough to catch up to Hookfang.
Fire: It seems to be more powerful then average sized Nightmares and has an enhanced fire range.
As a large dragon, this Monstrous Nightmare maneuvers around slower compared to other dragons like Hookfang. He is unable to make sharp turns or stop himself quickly. Also, he has difficulty flying through thick and dense forests and gets entangled in the branches and trees. Additionally, his large size hindered him while he was under the dome, making it hard for him to move and fight back against a smaller Hookfang. These weaknesses enabled Hookfang to defeat him, but this dragon was still a formidable opponent.
Hookfang's Nemesis is the first Titan Wing dragon seen in the series.
He has two claws on his wings instead of three like in Rise of Berk.