Chaos dragons had the typical draconic build, with muscular limbs and powerful wings, a serpentine neck and a mouth full of sharp teeth, and a jagged-edged tail, but their scale patterns and markings varied wildly between individuals. Additionally, some speculated that such markings changed over time.
Chaos dragons were creatures of chaos, and they essentially sought to undermine and destabilize society and civilization in general. The ones that tended towards good did so in order to promote positive change, while evil ones wished simply to spread violence and destruction.
Chaos dragons, like other planar dragons, had a fear-inducing aura. They also had two breathe weapons: a cone of confusion-causing gas, and a line of variable energy, the type of which not even the chaos dragon knew before unleashing it. Acid, cold, eletricity, fire, and sonic energies were all among the recorded possibilities.
Like all planar dragons, chaos dragons lacked the innate spellcasting of other dragon species but retained a set of spell-like abilities and other natural abilities. From hatching, they were immune to compulsion effects, as very young they began to be able to "cast" protection from law once per day, and as young they gained some resistance against nonmagical weaponry (a trait that also steadily increased over time). Juveniles and older could replicate chaos hammer and entropic shield thrice each day, while as adults they developed the ability to replicate dispel law and mind fog once per day. Old chaos dragon could mimic word of chaos once per day, while very old chaos dragon gained resistance to any most attacks except for those imbued with lawfulness. Finally, the ancient ones could mimic mislead once per day, and great wyrms could mimic cloak of chaos once per day.
Chaos dragons always opened combat with their confusion-inducing breath weapon in order to send their enemies into disarray, and then entering melee. They used their spell-like abilities against particularly irritating opponents.
Chaos dragons were native to Limbo, but were also reported to live in the Abyss, Arvandor, Brightwater, Dragon Eyrie, Gates of the Moon, Supreme Throne, Warrior's Rest Chaos dragons were known to live alone, in groups of up to five individuals while young, or as full families consisting of a mated pair and their offspring.
A group of githzerai attempted to forge an alliance with chaos dragons in an attempt to replicate the bond between the githyanki and red dragons. The effort was largely a failure due to the chaos dragons' unpredictability and disloyalty. However, some successful exceptions existed and, in rare cases, collaborations between chaos dragons and githzerai could be found.
Chromatic dragons: Red • Black • Blue • Green • White • Brown • Gray • Purple • Pink • Yellow
Gem dragons: Amber • Amethyst • Beljuril • Emerald • Sapphire • Topaz • Crystal • Obsidian • Ruby
Lung dragons: Chiang lung • Li lung • Lung wang • Pan lung • Shen lung • T'ien lung • Tun mi lung • Yu lung
Planar dragons: Astral • Battle • Blight • Chaos • Ethereal • Hellfire wyrm • Howling • Mirage • Oceanus • Pyroclastic • Radiant • Rust • Shadow • Styx • Tarterian
Epic dragons: Force • Prismatic
Catastrophic dragons: Volcanic
Miscellaneous dragons: Dzalmus • Mist • Radiant • Rattelyr • Song • Vishap
Draconic transformations: Air • Ascendant • Hidecarved
Linnorms: Corpse tearer • Dread • Stygian
Drakes: Ambush • Black firedrake • Dragonne • Elemental (Earth • Fire • Ice • Magma • Ooze • Smoke • Water) • Felldrake (Crested • Spitting) • Greater • Guard • Mind • Portal • Rage • Space • Vulture
Dragonets: Crow's-nest dragon • Draken • Faerie dragon • Firedrake • Pseudodragon
Dragonbloods: Draconic creature • Dragonborn of Bahamut • Dragonspawn
Drow-dragon (shadow) • Drow-dragon (deep) • Half-dragon • Kobold (Dragonwrought • Urd) • Weredragon • Zar'ithra • Zekyl
Undead dragons: Dracolich • Dragonwight • Ghost • Hoarder • Rathrea • Vampiric • Zombie