Zoan

Zoan is a type of Devil Fruit. This type of fruit allows the user to transform into an animal and animal-human hybrid forms at will.

Effects
Allows the user to transform into an animal. This fruit provides three forms: the user's natural form, a full animal form, and a hybrid form, combining both original and animal form into an odd bipedal form (usually in a bizarre way where the size is greatly exaggerated). The only known hybrid forms that are not bipedal is the Hebi Hebi no Mi series.

Strengths
Mainly improves physical abilities and allows the user to use his or her 3 forms to adapt to a situation during a fight to find the form that gives the biggest advantage.

In their hybrid form Zoan users experience enhanced senses, as this form uses a combination of both animals abilities. Skilled Zoans are also capable of using their powers to shape-shift out of harm's way; this is particularly useful, especially when the Zoan's body has been restrained, as Chopper demonstrated so many times (such as Chopper switching from heavy point to brain point). This type of fruit is considered the best for martial arts of the three types of Devil Fruit and is favoured by fighters and warriors alike.

This fruit type is most useful when applied to objects such as guns or swords, giving an otherwise inanimate object life and increasing its value to the owner of the item.

Weaknesses
They are limited to the capabilities of the animal they are able to transform into. However, in the case of the Human Human fruit (and most likely all cases with the Zoan Devil Fruit types), it is not totally wasted if the species consumes the fruit of the same nature. If a human ate the Human Human fruit, they would become enlightened.

Furthermore, inanimate objects animated to life through the use of the Zoan fruits seem to involve certain requirements in order for the owner to acquire their loyalty (for example, Funk Freed, Spandam's sword, has shown the need to be fed). Also, these once-inanimate objects gain their own free will and physical weaknesses, such as Funk Freed fearing death and Lassou contracting a cold.

Sub-Categories
Despite being a Devil Fruit that grants generally only three forms to the user, the Zoan class has many subcategories, making this class a versatile Devil Fruit.

Regular Zoan
This is the most commonly seen Zoan-class Devil Fruit. It allows the users to transform into a certain animal. Even though most animals derived from this category are docile, the forms still grant increased strength. This category is most used for inanimate objects, such as a dog-gun and an elephant-sword, or given to other animals for transportation, such as Pierre, a bird-horse.

Carnivorous Zoan
As stated by Tony Tony Chopper, carnivorous animals are more predatory and bloodthirsty than others by nature, and because they are evolved to hunt and kill, they are more battle-adept, and as such, more dangerous and powerful in combat. Only two fruits from this category are shown: both belonging to CP9 members Rob Lucci (Leopard) and Jyabura (Wolf).

Ancient Zoan
As stated by Scratchmen Apoo, this is apparently a much rarer Zoan-class Devil Fruit than the normal types, and allows the users to transform into ancient and extinct animals. Only one has been shown, wielded by X. Drake.

Awakened Zoan
Aside from transforming into a powerful animal, it seems that this category allows the users to get back up faster after being knocked unconscious. Whether this "awakened" status applies to Zoan alone, or other classes is yet unknown. The four Demon Guards each wield one of these fruit powers.

Other Information
The name "Zoan" for these types of Devil Fruit likely comes from the medical term zoanthropy, where the sufferer believes he is suffering from lycanthropy - changing from human to animal form.

While most Zoan users can only use the three forms, the Straw Hat Pirate's doctor Tony Tony Chopper can utilize more forms for a given amount of time with the aid of the "Rumble Ball", which he developed. It's unknown if other Zoan users can also be affected by the Rumble Ball since so far only Chopper has eaten it. However, consecutively eating two or three under six hours can cause disastrous results, as the tampering with a Devil Fruit's powers is not something meant to be done.

A majority of the Zoan Devil fruits also come in different "models" that result in variations of the animal. For example, the Inu Inu (Dog) Fruit has Jackal, Dachshund, and Wolf models, the Ushi Ushi (Bull or Cow) Fruit has Bison and Giraffe models, and the Neko Neko (Cat) Fruit has a Leopard and Cheetah models.

List of Zoan Fruits

 * Inu Inu no Mi (Dog) series:
 * Inu Inu no Mi, Model: Jackal (English dub: Mutt-Mutt Fruit: Jackal Strike/Dog-Dog Fruit: Model Jackal/Mutt-Mutt Fruit: Jackal Mode)
 * Inu Inu no Mi, Model: Dachshund (English dub: Mutt Mutt Fruit/Mutt Mutt Fruit, Dachshund Type)
 * Inu Inu no Mi, Model: Wolf
 * Ushi Ushi no Mi (Cow) series:
 * Ushi Ushi no Mi, Model: Bison (English dub: Ox-Ox Fruit/Ox-Ox Fruit, Bison Model)
 * Ushi Ushi no Mi, Model: Giraffe
 * Neko Neko no Mi (Cat) series:
 * Neko Neko no Mi, Model: Leopard (English dub: Cat-Cat Fruit: Model Leopard)
 * Tori Tori no Mi (Bird) series:
 * Tori Tori no Mi, Model: Falcon (English dub: Tweet-Tweet Fruit/Tweet-Tweet Fruit, Falcon Type)
 * Hebi Hebi no Mi (Snake) series:
 * Hebi Hebi no Mi, Model: Anaconda
 * Hebi Hebi no Mi, Model: King Cobra
 * Single model series:
 * Hito Hito no Mi (English dub: Human-Human Fruit)
 * Mogu Mogu no Mi (English dub: Diggy-Diggy Fruit)
 * Uma Uma no Mi (English dub: Horse-Horse Fruit)
 * Zou Zou no Mi
 * Ancient type:
 * X. Drake's unnamed Devil Fruit, allows him to take the form of a dinosaur.