Dungeons & Dragons 5e Element 133 Class Feature: Mountain: Thunderous Blows

Your size instills you with the strength to batter around your foes, making any battlefield your domain. Once per turn, when you damage a creature with a melee attack, you can force the target to make a Strength saving throw (DC 8 + your proficiency bonus + your Strength modifier). On a failure, you push the target 5 feet away from you, and you can choose to immediately move 5 feet into the target’s previous position.

In addition, All of your melee attacks gain the siege property (your attacks deal double damage to objects and structures). Your melee attacks against creatures of the construct type deal an additional 1d8 weapon damage.