"Batto" is the Japanese pronunciation for the word "bat".
In the English subs, it is called the Bat-Bat Fruit: Model Vampire.
The Batto Batto no Mi is a purple tomato-shaped fruit with swirl patterns around it and a curly green stem resembling a tail. The fruit is small enough to be held easily in a man's hand.
Strengths and Weaknesses
The main strength of the fruit's power is that it allows the user to transform into a full vampire or hybrid form. This also allows flight, the ability to create a shroud to cloak himself, and the ability to suck someone's life force from their bodies either by biting their neck or digging his nails into the victim's skin. By sucking his victim's life force, he can age them and regain his own youth, with Red implying the fruit grants immortality and eternal youth as long as there is life force for the user to drain. The user also shows an apparent form of teleportation by appearing and disappearing in blood-red bursts of energy.
There were no ill effects to the victims after their life force was returned. Otherwise, it has standard Devil Fruit weaknesses.
Redfield is seen flying with his wings and attempting to suck Yadoya's life force. He later sucks Luffy's life force, leaving him in a state similar to aging him by many years. Luffy is left with white hair and gray skin, and his aged body makes it difficult for him to fight. He uses the wings and claws to swipe and or cut his opponent.