The green dragon, D, is a monster that appears in NetHack. It has a younger form in the baby green dragon, D. The green dragon has poison resistance both intrinsically and from its scales, and its breath weapon fires rays of poison that leave behind clouds of gas. Its corpse is poisonous to eat, but grants poison resistance.
Players will not see baby green dragons through normal random monster creation outside of the Oracle and Sokoban levels, although they can be hatched from dragon eggs; adult green dragons start appearing around the midway depths of the dungeon. Green dragons can be generated in throne rooms as early as dungeon level 15, and may appear when a throne at this depth or lower is looted. Green dragons can also be generated if a lawful spellcaster casts the summon nasties monster spell.
- See also: Dragon#Strategy
While poison resistance is the one you are most likely to have by the time you encounter these dragons, the poison gas clouds their breath attacks leave present an entirely different problem. Without poison resistance, being caught in the stream of poison can kill you alarmingly fast - with poison resistance (or a source of reflection to deflect the blast), the damage and threat of death is severely lowered, but the gas clouds can still leave you blinded. Be sure to get out of the clouds as soon as possible, then cure the blindness as soon as possible (e.g., with a unicorn horn), especially if you have not obtained telepathy yet.
However, it is possible to use the poison gas against other monsters, especially if you have a source of conflict. Monsters lacking poison resistance that are caught in the clouds are subjected to the same effects, and will be left severely weakened from a few turns of exposure if they are not killed outright, potentially making for easier targets.
NetHack 2.3e introduces the green dragon along with all of the other modern dragon types and their breath weapons, except for silver.
NetHack 3.0.0 introduces baby green dragons alongside the other baby dragons. This version also distinguishes all color dragons, their younger stages and their corpses, and introduces dragon scale mail.
NetHack 3.1.0 introduces green dragon scales along with the other colors, as well as the current method of obtaining dragon scale mail.
The green dragon's breath leaving trails of poison gas behind is a feature introduced in NetHack 3.6.1.
Variants of NetHack often subject dragons to extensive changes, including the green dragon.
In the biodiversity patch, the green dragon is renamed to the wyvern.
As with all other dragons in SLASH'EM, baby green dragons have a base level of 4 instead of 12, and can be encountered via random generation in ordinary levels with a frequency of 2; they are also eligible for creation on many levels that generate random D on level creation. Adult green dragons have a base level of 18 instead of 15.
Baby green dragons hit as a +1 weapon, and adult green dragons hit as a +3 weapon. Adult green dragons will not turn traitor while tame.
In the West the dragon was the natural enemy of man. Although preferring to live in bleak and desolate regions, whenever it was seen among men it left in its wake a trail of destruction and disease. Yet any attempt to slay this beast was a perilous undertaking. For the dragon's assailant had to contend not only with clouds of sulphurous fumes pouring from its fire breathing nostrils, but also with the thrashings of its tail, the most deadly part of its serpent-like body.
"One whom the dragons will speak with," he said, "that is a dragonlord, or at least that is the center of the matter. It's not a trick of mastering the dragons, as most people think. Dragons have no masters. The question is always the same, with a dragon: will he talk to you or will he eat you? If you can count upon his doing the former, and not doing the latter, why then you're a dragonlord."