AC 13 + DEX when not wearing armour

Your Strength score increases by 2 and Constitution score by 1.

Half-dragons live about twice as long as a member of their base race. Given that here it is a Goliath which can live up to a century that would give you a maximum of around 200 years old, like dragons they grow quickly. They walk hours after hatching or being birthed, attain the size and development of a 10-year-old human child by the age of 3, and reach maturity by 15.

A half-dragon generally follows the precepts and the beliefs of his or her Dragon parent, adopting the alignment and beliefs typical of that dragon parent's kind. There are those who rebel against their dragon parents and their parents' alignments, though. Instances of this behavior are more common among chromatic half-dragon paragons--but the evil dragons are often keen to destroy rebellious offspring. As a result, half-dragon paragons with unexpected alignments are rare among both metallic and chromatic varieties.

Similar to Dragonborn's, Half Dragons are taller and heavier than humans, given their Goliath Parentage they stand well over 8 feet tall and averaging almost 340 pounds. Your size is Medium.

Your base walking speed is 30 feet, your wings afford you a flying speed of 60, thanks to your tail your base swimming speed is also 30 feet.

You have draconic ancestry. 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 2d6 damage on a failed save, and half as much damage on a successful one. The damage increases to 3d6 at 6th level, 4d6 at 11th level, and 5d6 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, Giant and Draconic. Draconic is thought to be one of the oldest languages and is often used in the study of magic. The language sounds harsh to most other creatures and includes numerous hard consonants and sibilants.

Thanks to your Dragon blood, you have superior vision in dark and dim conditions. You can see in dim light within 120 feet of you as if it were bright light, and in darkness as if it were dim light. You can’t discern color in darkness, only shades of gray.

Thanks to your Dragon blood, you have heightened senses. You can perceive your surroundings without relying on sight up to 10 feet away from you.

You have proficiency in the Athletics skill.

You can focus yourself to occasionally shrug off injury. When you take damage, you can use your reaction to roll a d12. Add your Constitution modifier to the number rolled, and reduce the damage by that total. After you use this trait, you can’t use it again until you finish a short or long rest.

You count as one size larger when determining your carrying capacity and the weight you can push, drag, or lift.

You’re acclimated to high altitude, including elevations above 20,000 feet. You’re also naturally adapted to cold climates, as described in chapter 5 of the Dungeon Master’s Guide.