Ironshod Trotters

These boots have iron horseshoes embedded in their soles. When you take the Dash action to run while wearing the boots, you can move an extra 10 feet.

As an action, you can click the boots together to cast the polymorph spell on yourself to transform into a riding horse. The horse has a carrying capacity of 480 pounds and a walking speed of 60 feet. Your game statistics are replaced by the riding horse’s statistics, but you retain your alignment, personality, and Intelligence, Wisdom, and Charisma scores. You also retain all of your skill and saving throw proficiencies, in addition to gaining those of the creature. Your gear melds into the new form. You can’t activate, use, wield, or otherwise benefit from any of your equipment while transformed. Any bags you were carrying do not meld into your new form, and are magically draped over your torso as saddlebags.

You remain in this form for up to 8 hours or until you end it as an action. Taking any damage while transformed causes you to revert to your normal form early and take the damage as normal. Once this property of the boots has been used, it can’t be used again until the next dawn.