Kaihen Kaihen no Mi aka the Modification fruit, the one that eats such will become a modification human, allowing them to modify themselves, others or objects with ease, it is best used by someone with a good head on their shoulders for optimal results though it can still be used to modify someone's body poorly, leading to health issues if one is so cruel.
An odd looking fruit with a gear like shape, its taste is bitter from its outside to its green inside's.