race features:
Poison/Fire Breath Weapon: You may use this as an Action. Choose between either a line attack (5 by 30ft ft ) or cone (15ft) per use. When you use your breath weapon, each creature in the area of the exhalation must make a Saving Throw. The DC for this saving throw equals 8 + your Constitution modifier + your proficiency bonus. A creature takes 2d6 Poison or Fire damage on a failed save, and half as much damage on a successful one. If Poison damage, it is produced as a cloud and hangs in the air. Dealing Poison damage to anyone who ends their turn in it. The damage decreases by 1d6 at the end of your turn until it disappears completely or wind blows it away. 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.
Resilient Body: You reduce every instance of Poison Damage by 25 points of damage. Your lungs filter out poison so it doesn't effect you. You have Advantage on all Saving Throws involving poison.
Climber's Body: You have Advantage on all checks to climb and have a climbing speed of 30ft. Your jumping distance is also doubled.
"They strangely isolationist and are the second most athletics of the dragonborn. Their bodies are well adapted to climbing and bounding through treacherous areas. They have visible gaps in their scales where you can see flesh underneath. Normally these gaps are only wide enough to fit a fingernail into."