Yama Yama no Mi

The Yama Yama no Mi (山山 ) is a Zoan-type Devil Fruit that allows its user to transform into a hybrid or full version of a wild boar. Yama (山 ) coming from Yamakujira (山鯨 ) meaning “Wild Boar”, in both Viz Manga, and the FUNimation dub, it is called the Boar-Boar Fruit. This fruit was originally put into the hands of a marine, however that marine was killed by Kojirō Uesugi, the current captain of the Tyrant Pirates and this fruit is used in combination with his weapon the Senshu no Tekken.

Strengths
The main strength of this fruit as demonstrated by Kojiro, is that he is able to transform into a hybrid or full version of a wild boar. With this he is able to go into a hybrid form, gaining immense strength, speed and stamina. He had revealed that he had a few different modes that he can go into, but thanks to a special wine he drinks that was created by Tensoba Zaimon. Much like Choppers would rumble ball, Kojiro can break down the only two forms and he is able to have a few new features. Also through the use of the life return, Kojiro has shown to increase his size greatly and muscles as well.

Weakness
The user will suffer the standard affects of the devil fruit.