Source: Unearthed Arcana 83 - Giant Options

Prerequisite: 4th Level
You’ve manifested the resilience emblematic of hill giants, granting you the following benefits:

Bulwark. When you are subjected to an effect that would move you at least 5 feet or knock you prone, you can use your reaction to steady yourself. You are then neither moved nor knocked prone.
Hearty Health. When you are subjected to a spell that restores your hit points, you can regain additional hit points equal to your Constitution modifier. You can regain these additional hit points a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.