Astral Dragons

The astral dragon is a rare species of chromatic dragon that has adapted to the Astral Plane, they while technically being chromatic lack some of the defining features of their kind like their natural evil nature making astral dragons tend to be neutral. They are aggressive but only to those they consider invaders of the astral plane since they consider themselves to be their defender. Their bodies are slim and snake-like without wings adapted to fly without gravity in the astral plane. They, however, can easily fly in the material plane thanks to a magic organ in their brain that nullifies the effects of gravity. Astral dragons horns are also peculiar since they look more like reindeer antlers than horns and with age, the horns crack, twist and grow giving them the look of tree branches. They despise walking and are almost always floating this is because they are physically weaker than other dragons and when they walk in the material plane the can not lift their entire body dragging their tail behind which gives them in their own words "an undignified look". Their breath weapon has also evolved to the conditions of the astral plane becoming an abrasive spray of astral dust and psychic winds, they also have a second breath weapon with the ability to short circuit the brain of its victims leaving them unable to use magic, magic items, speak, use tactics, etc. But the most dangerous aspect of this breath weapon is when it is used in the astral plane. The reason being that the astral plane is a plane of thought and the only way to move is by using your mind, so if your mind is fried you become easy prey for the dragon especially if the victim was a caster.

The Eternal Dragons

Above the physical differences, above their alignment what truly separates the astral dragon from any other kind of dragon is its incredibly long life span. The astral plane is a weird place to call home since time doesn't flow and body functions are slowed to a crawl, this forces the astral dragon to travel to other planes to be able to grow and heal without the use of magic, this also has the effect of making the dragon only age when he desires to, making it technically immortal.

Masters of Magic

Astral dragons are along with gold dragons one of the few types of dragons who casts spells as wizards do but unlike gold dragons who need strick studies to gain this skill, astral dragons are born with the ability to cast spells like wizards and are incredibly skilled at it. They are able to wield more spells slots that normal and with their life span they can gather libraries worth of spells and magic items even spells who are believed to be lost and new spells created by them. Their skills with magic are so mighty that those who know about the astral dragon believe that they hold the secrets of casting spells of 10th level and above like in times before the prohibition imposed by Mystra.

Astral Travellers and the Sickness

Astral dragons have the innate ability to travel at will from any plane to another as per the spell plane shift, they can only teleport themselves and what they are holding and is an essential part of their life since this is how they explore, gather treasures, age, reproduce... etc. They are able to do it thanks to a special organ in their brains, this organ also grants them the ability to float in the material plane. This teleportation ability comes with a risk, each time they plane shift to a plane other than the astral plane there is a 1% chance that the dragon will develop an illness that damages the organ in the brain that allows teleportation losing the ability to plane shift forever. This sickness is called astrolomitis and if the dragon suffers this while outside the astral plane the sheer stress of it will make it go mad and go in a berserker rage destroying and eating everything in his path until days later it dies of exhaustion. Teleporting a sick astral dragon back to the astral plane restores his sanity in a couple of days but only a wish spell is able to cure it and grant the dragon his ability to plane shift back. 

Astral Dragons Eggs

A female astral dragon produces a single egg every 100 years, its 5 feet in diameter and the mother carries it everywhere she goes. This is why astral dragons are often depicted or seen carrying a small orb when traveling. The eggshell is the color of the astral plane making it very difficult to spot. The egg grows with time up to 10 feet diameter and magically creates a hole in the top to indicate the wyrmling that is ready to leave, the mother knows to leave the egg in the astral plane when this hole appears. The egg and the dragon are magically linked allowing the dragon to always know where his egg is, the egg also has the magical property to grow even after the wyrmling has left as to serve as a lair until the dragon is old enough to find a lair for himself.

Guardians of the Astral Plane

Astral dragons consider themselves protectors of the astral plane, guarding it against outsiders and invaders but they hold a special grudge against the Githyanki. The astral dragons barely need to eat but they do enjoy it, their favorite meal is Githyanki meat. Like all other dragons, astral are solitary except when they cooperate to raid a Githyanki settlement, this is the reach of their hate for this race. Since the Githyanki are allied with Tiamat their confrontations usually end in a fight between astral and red dragons. 

The Treasury 

Astral dragons travel to other planes constantly especially in their wyrmling state since they need to do this in order to age, and like any dragon, they seek treasures so they use this opportunity to gather magic and valuable items from all the planes they visit. The hoard of a young astral dragon will probably look the same as any other dragon maybe with more emphasis on magic items and scrolls but as they age and develop their skills in the arcane arts their hoards will start to resemble more a museum of artifacts or a magic library. They love to investigate magic and to create new magic items or spells and will trade for them with travelers as long as the dragon doesn't consider them a menace to his home. Outsaiders of the astral plane may think that astral dragons favorite treasure are magical items but this is false, for they have a weakness for a particular type of gemstone, the moonstone. They adore this type of gems for various reasons, it's the same color as the astral plane reminding them of their home while they travel and making it easy to hide in their hoard. But the principal reason is that astral dragons believe that moonstones have psychic abilities capable of increasing their control over gravity and that it makes the organ in his brain more difficult to malfunction and develop astrolomitis.

Embodiment of Freedom

Astral dragons have a great sense of freedom as they constantly use their plane shift ability to explore different locations on different planes especially when they are young. If an astral dragon somehow finds himself captured or trapped for any reason in the material world they will do anything necessary to regain their freedom. They are incredibly hard to capture so the only feasible way for this to occur will be an astral dragon with astrolomitis that has managed to keep his sanity and now seeks a cure or a way back to the astral plane. Astral dragons also have a strange sense of honor when it comes to promises, almost never making one for they think that making one binds you to fulfill it and binds you to the plane of the creature you made the promise, contradicting their love for being free and yet whatever they promise they always fulfil. Because of this, finding an astral dragon willing to make a promise is extremely difficult with one exception, the cure for astrolomitis. Since they are left alone to grow and explore you may think of the astral dragon as a not very social dragon and its true in part but they do enjoy other dragons company especially when trading magic or raiding Githyanki settlements, because of this offering a way to heal astrolomitis is always a sure way to make an astral dragon make a promise even if they don't suffer the illness. Especially if the cure offered is a wish spell after all, who better than an astral dragon seeker of knowledge and arcane might to understand the value of a spell such as wish used for the sake of others.