Trample (5e Feat)
From D&D Wiki
Prerequisites: size of Medium or greater
Each time you move more than half your total movement speed and then make a melee weapon attack against a creature of the same size or smaller than you, they are forced to make a DC 10 or half damage taken, whichever is higher, Strength saving throw. On a fail, they take 1d4 bludgeoning damage and are knocked prone.