Question: Taking several notable real life inspirations from the animal kingdom I like to design a realistic Dragon towering any creature ever lived but has a nasty habit of generating sonic boom every where in its wake. What are the prerequisites my Dragon have to evolve in order to attain supersonic flight? 

I think it's must have close to a mammal blood circulation to supply ample oxygen to its already effective muscular system and is warm blooded like a cheetahs to give it energy for sudden rush of adrenaline, a crocodiles eyelids to cover it eyes, and so on. My concern is that this colossal winged breast would be too heavy and its skeletal structure have to be augmented naturally through evolution but I have no clues how any animal can survive unhurt after performing such a earth shattering feat any ideas? No tech pls and absolutely no thunderpants!

Answer: 
**Dragons would need to have a reason to be supersonic in order to evolve to do so.**

Being able to fly at supersonic speeds will have incredibly high metabolic and structural costs for the dragon. In order for one to evolve these traits, we need to answer the following question: why do supersonic dragons produce more offspring than non-supersonic dragons?

If supersonic flight doesn't get more food, or more mates, dragons won't evolve it. Similar non-supersonic dragons would outcompete the supersonic ones, since they would require far less food.

In nature, nothing else flies supersonic, and supersonic flight won't be worth its calories if its used to catch cattle or ponies or other such animals. That's not to say that it couldn't be useful, though. Dragons have projectile weapons, so if dragons mostly fight against other dragons, supersonic flight could give them a key edge in dogfighting, especially since the dragon they were closing in on wouldn't be able to hear them coming.

**Dragons would need to consume incredibly high caloric density food in order to evolve to be supersonic.**

It takes a *lot* of energy for an aircraft to reach supersonic speeds, probably more than an animal could obtain eating other animals. If dragons fly at supersonic speeds, they'll need to consume something more energetically dense. Something like oil.

If dragons consume oil from naturally occurring sources, they could directly burn this in an internal jet engine in order to achieve supersonic flight.

**The Ecology of Dragons**

Dragons are large creatures that eat oil. They both extract calories from it, and produce refined fuel which they burn in their engines. These engines resemble a pulse-jet engine, and are primarily comprised of carbon fibers and thermally resistant graphites which the dragons synthesize from their food.

Naturally occurring oil, of course, is rare, and as a result, dragons have become incredibly territorial. They've got large, stiff bodies covered in smooth scales to reduce their drag, and can launch flaming globs of tar at one another mid flight. Large dragons can fly at supersonic speeds, which gives them maneuvering advantages in their aerial fights over oil-rich territory. Because their bodies are stiffened for high speed flight, they can't turn their heads very much, so skill in dogfighting is key for dragons to protect their territories.

These supersonic dogfights, of course, are necessarily short, as the thick scales of graphite that dragons grow on the leading edges of their wings and along their heads slowly ablate during supersonic flight. Dragons prefer to cruise at fast subsonic speeds and use their size and breath weapons to dispatch smaller challengers if possible, rapidly accelerating into the supersonic regime only when absolutely necessary to outmaneuver an opponent. These graphite scales also provide a measure of resistance against the breath weapons of other dragons.

Larger dragons can grow these heat shields faster and thicker than smaller dragons. As this gives the largest of these creatures a major edge in combat, evolution has driven these majestic creatures to grow to truly colossal sizes.
A creature meeting your size, speed, and strength requirements would have to be composed of extremely lightweight tissues, most notably including the skeleton (which must be able to handle the physical stresses of accelerating to supersonic speeds rapidly) and muscles (which must be able to convert the creature's biochemical or magical energies into mechanical energy efficiently, rapidly, and at high volume).

The most "realistic" way I could imagine all of these requirements being satisfied is if your dragon looks like a blimp: a giant sack of air that moves short distances by flapping its wings, and naturally floats in the air because its body density is about equal to the surrounding air density. Such a creature might achieve supersonic speeds by rapidy forcing most of the air in its body cavity through a small opening to create jet propulsion. This would also cause the creature to deflate to a narrow, streamlined shape that's more aerodynamic for long, straight flight paths.

We could go into further technical detail, but as you can see the result is a bit ridiculous. Really what I'm saying is you need a fart dragon.