Source: Xanathar's Guide to Everything

Prerequisite: Dwarf

You have the blood of dwarf heroes flowing through your veins. You gain the following benefits:

• Increase your Constitution score by 1, to a maximum of 20.

• Whenever you take the Dodge action in combat, you can spend one Hit Die to heal yourself. Roll the die, add your Constitution modifier, and regain a number of hit points equal to the total (minimum of 1).