Plainsborn (5e Race Variant)
From D&D Wiki
Plainsborn Humans are still humans, but rather in the short end, with most if not all Plainsborn only reaching a maximum height of 5'0" with maybe some lucky few reaching a height of 5'3". These people are nomadic by nature, having learned to run to their destinations for quite some time, with some even capable of running all the way there. These people have inhabited mostly plains and grasslands, but some can be found in tundras and mountainous areas.
Thanks to their great stamina and endurance, these people make great scouts and messengers, capable of running to multiple positions in only a day while some may take two or three days. They've also adapted to being able to see in the dark, having have to make many dangerous treks during the night to avoid conflict or danger.
Ability Score Increase. Your Dexterity score increases by 2 and your Constitution increases by 2.
Darkvision. You can see in dim light within 60 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.
Fleet of Foot. Your base walking speed is 40 feet.
Great Endurance. You ignore all nonmagical difficult terrain and any Exhaustion you gain is treated as one point less.