The Ryu Ryu no Mi, Model: Pachycephalosaurus is an Ancient Zoan-type Devil Fruit eaten by Ulti, a Tobiroppo officer of the Beast Pirates.

This fruit allows Ulti to transform into a Pachycephalosaurus or hybrid form, specializing in headbutt-based attacks. The defining feature of this Devil Fruit is the user’s ability to deliver devastating high-impact blows using reinforced skull strength, combined with Ancient Zoan durability.

Ulti frequently pairs this power with her aggressive fighting style during the Wano Arc.