Uma Uma no Mi

This Zoan-class fruit lets whoever eats it change at will into either a part-horse hybrid or a fully formed steed. Its name comes from uma, Japanese for horse, and the VIZ and Funimation versions title it the Horse-Horse Fruit. The power belongs to Pierre, the riding bird kept by the Skypiea knight Gan Fall, and it entered the story during Chapter 238.

The fruit's effect is simply the on-command horse transformation, available in both partial and complete forms. No special drawback has surfaced for it, so the wielder contends only with the standard set of weaknesses that burden every Devil Fruit eater.

Pierre is the sole user. Because his original bird body already stands tall enough to serve as a mount, the transformation mostly exists so Gan Fall can claim a Pegasus for a steed, the winged look coming from the bird retaining its feathered wings in hybrid shape. In horse or hybrid form Pierre will also bite anyone who shows disrespect toward his master, as Usopp once learned.