Hito Hito no Mi, Model: Onyudo

The Hito Hito no Mi, Model: Onyudo is a Mythical Zoan-type Devil Fruit that allows its user to transform into an Onyudo, a large monk yokai, at will. It was eaten by Onimaru.

Etymology

 * "Hito" (人) is Japanese for "human".
 * "Ōnyūdō" (大入道) is a Japanese Yokai that takes the form of a gigantic monk.

Strengths and Weaknesses
This fruit grants the user to transform into an Ōnyūdō a mythical yokai that takes form of a gigantic monk, with this fruit being in the Hito Hito no Mi variation it grants the user human like intelligence if eaten by a non-human e.i. an animal like Onimaru.

So far there is no known specific weakness for this devil fruit besides the standard devil fruit weaknesses.

Usage
Onimaru is able to transform into an Onyudo, who is known as Gyukimaru. As Gyukimaru, he is capable of human speech.

Befitting his size, Gyukimaru has enormous strength as he could match Zoro's physical power. He also has great speed, able to match Zoro's agility, though in their next match, he was overwhelmed by Zoro, implying he might have had an advantage in the first match because he caught the swordsman off-guard.