Ningyo Ningyo no Mi

Introduction
Ningyo Ningyo no Mi (lit. Merfolk-Merfolk Fruit) is a Zoan-class Devil Fruit that allows the user transform partially or fully into a merfolkk. It was eaten by ?????.

Weaknesses
The user ironically suffers from the standard Devil Fruit weaknesses since Merfolk usually swims in the water but can not due to losing the ability to swim. However, the user can still breath underwater even though weaken by being in water.

Trivia

 * This devil fruit is oddly inconvenient because Devil Fruits usually give the consumer an advantage but Devil Fruits takes the user's ability to swim  Merfolk usually live in the ocean and can quickly manever in the water rather than on land.
 * People have commented if the rumored devil who makes devil fruits made this certain devil fruit as a joke.