Aasimar

Aasimar bear within their souls the light of the heavens. They are descended from parents with a touch of the power of Mount Celestia, the divine realm of many lawful good deities. The parents, or distant ancestor of an Aasimar could have struck a bargin with a divine being, or perhaps their child had simply been chosen by the Gods for some purpose greater than their own. Aasimar are born to serve as champions of the gods, and their births often hailed as blessed events; although in a land suspicious of the arcane, it can also be a death sentence for a child. They are a people of otherworldly visages, with luminous features that reveal their celestial heritage. From an early age, an aasimar receives visions and guidance from celestial entities via dreams. These dreams help shape them, granting a sense of destiny and a desire for righteousness.
Aasimar, are historically been a rare sub-type of human, although an Aasimar could be born of any race. More recently, many Tieflings Aasimar are born as champions of The Guiding Light in the Lightforged Realm of Morencia. 
Aasimar are typically of medium-size and share a heritage and bond with the celestial powers or whose soul has been touched by the divine. Visually Aasimar stand out from their humanoid cousins because they literally radiate the powers of their deity. Individual appearances can vary, but most Aasimar have glowing eyes, a skin of bright colours which seems to (but doesn't) glow, and often has hair which glows as well.

Hidden Wanderers

While aasimar are strident foes of evil, they typically prefer to keep a low profile. An aasimar inevitably draws the attention of evil cultists, fiends, and other enemies of good, all of whom would be eager to strike down a celestial champion if they had the chance. When traveling, aasimar prefer hoods, closed helms, and other gear that allows them to conceal their identities. They nevertheless have no compunction about striking openly at evil. The secrecy they desire is never worth endangering the innocent.

Conflicted Souls

Despite its celestial origin, an aasimar is mortal and possesses free will. Most aasimar follow their ordained path, but some grow to see their abilities as a curse. These disaffected aasimar are typically content to turn away from the world, but a few become agents of evil. In their minds, their exposure to celestial powers amounted to little more than brainwashing. Evil aasimar make deadly foes. The radiant power they once commanded becomes corrupted into a horrid, draining magic. And their angelic guides abandon them.
https://www.dndbeyond.com/races/aasimar - for stats and details