This is an ordinary arrow while held, carried, or otherwise motionless. When fired, the arrow’s size becomes Medium when it is 5 feet or farther from the creature who fired it. It deals 8d8 piercing damage on hit, and if the target is Large or smaller, the creature must make a Dexterity check or be encumbered by the arrow and move at half speed. The arrow counts as magical for the sake of overcoming immunities and resistances.