Kobold, Draconic Servant (5e Race Variant)
From D&D Wiki
Not all kobolds adhere to the non-elemental form of their god, Kurtulmak. As servants of dragons, some devote themselves deeply to their chromatic masters. In exchange, their blood changes to suit that of their ruler, marking them and their kin as property. Such kobolds more often serve, or have served, within dragon lairs rather than their own nest of tunnels. So as to not disgrace themselves before their master, they are far more bold than the usual kobold.
This race variant replaces the grovel, cower, and beg trait.
You instead gain the dragon's resistance trait.
Dragon's Resistance. Your body is branded with the scale color to match your masters. Choose a type of dragon from the below list; this determines the type of resistance you gain.