Your Strength score increases by 2, and your Charisma score increases by 2, and you Constitution score increases by 2.

The lifecycle of a dragon has a magical component. You are an ancient dragon more than 500 years old. Dragons increase in size slowly over hundreds of years eventually becoming gargantuan if they live long enough. A dragon’s natural lifespan is around 1200 years although some live much longer.

Dragons tend to the extremes of alignment based on their subtype. You are not typical of your race and may choose any alignment.

As an ancient dragon your size is gargantuan. 

Your base walking speed is 40 feet. You also have a flying speed of 60 feet as well. 

You have a dragon breath weapon and resistance. Choose one type of dragon from the Draconic Ancestry table. Your breath weapon and damage resistance are determined by the dragon type, as shown in the table.

Draconic Ancestry

You can use your action to exhale destructive energy. Your draconic ancestry determines the size, shape, and damage type of the exhalation. When you use your breath weapon, each creature in the area of the exhalation must make a saving throw, the type of which is determined by your draconic ancestry. The DC for this saving throw equals 8 + your Constitution modifier + your proficiency bonus. A creature takes 8d6 damage on a failed save, and half as much damage on a successful one. The damage increases to 12d6 at 6th level, 16d6 at 11th level, and 20d6 at 16th level. After you use your breath weapon, you can’t use it again until you complete a short or long rest.

You have resistance to the damage type associated with your draconic ancestry.

You can speak, read, and write Common and Draconic. 

You have darkvision to 60 feet. 

You are proficient with your bite. It is a natural melee weapon that deals 1d12 plus strength modifier piercing damage.

You have begun to master your innate magical abilities and as such you can as an action polymorph yourself into any medium or small humanoid you have seen.