The Monstrous Nightmare is a dragon seen throughout the How to Train Your Dragon book series.
Monstrous Nightmares are styled rather devilishly, with two curved horns on their heads, and physically resemble a western-style dragon.
Nightmares vary in size, but can be the largest of the hunting dragons. They are rated as Size 3 in The Incomplete Book of Dragons, placing them in the same size category as small Riding Dragons such as the Chickenpoxer or Zebramount.
To note: The Incomplete Book of Dragons and the "Viking Dragons and Their Eggs" Info Page in How to Train Your Dragon give different stat numbers.
Monstrous Nightmares have excellent senses - eyesight, smell, and hearing. This makes them excellent hunters. They are intelligent and can speak Dragonese, as well as be rather devious.
Behavior and Personality
Monstrous Nightmares are portrayed as rather selfish, vicious, and sly.
By unofficial Viking law, only the chief, or the son of the chief, can own one. Despite this, Snotface Snotlout, the nephew of the chief, acquires one named Fireworm, while Thuggory the son's chief from the Meathead Tribe owns another named "Killer".
Another unnamed Monstrous Nightmare appears very briefly, actually acting heroically.
- "One hunting dragon went down in a blaze of flames, a Monstrous Nightmare belonging to Very Vicious the Visithug that sank its teeth into the neck of a much larger Grimwing, which then grabbed it around the throat, and snapping, biting, and screaming down they went, doomed, into the Gorge in a somersaulting ball of fire."
- ―How to Steal a Dragon's Sword
Monstrous Nightmares appear in this reference book and in the 'Dragon Key' table at the back of the book.