An Artificial Devil Fruit is an apple shaped fruit with a long stem that curls at the end. They are rather small compared to natural Devil Fruits, and due to being man-made, its patterning is also different: instead of swirls covering the fruit, it has ring patterns. While Vegapunk's failed version is light colored all the way with a long swirled stem, the SMILEs manufactured through the co-operation of Caesar and Doflamingo are dark with light ring pattern with a short stem.
Unlike a natural Devil Fruit, it does not seem to have an unimaginably horrible flavor that one would describe as to the point of taking poison, as Momonosuke ate the entire fruit in bites without recoiling at the very least.
The Artificial Devil Fruit is created based on Vegapunk's research on how Devil Fruits affect the user's "lineage factors" (血統因子,kettō inshi?), making practical applications of such effects on the blood.
The fruit created by Vegapunk does not have a classified name due to being a failure. It allows the user to transform into a pink, serpentine dragon that bears a resemblance to the Chinese or Japanese variety.
It is later revealed that Kin'emon's son, Momonosuke, got changed into a dragon (龍,Ryū?), shown to have a more oriental appearance than the dragons encountered earlier by the Straw Hats, and the power to produce clouds. He was found in the garbage dump by Luffy after his battle with Monet and later explained about how he ate an artificial Zoan-type Devil Fruit.
His transformed size seems to be inferior compared to a natural Zoan-class Devil Fruit user's full-form transformation, as he was barely big enough to carry Monkey D. Luffy, a normal-sized human. His clothes seemingly disappeared completely when he changed. He also gained the ability to generate semi-solid clouds that could also be used as stepping stones, giving the appearance of flight. It is currently unknown whether or not Momonosuke's size in his animal form is due to his young age or an imperfection in the fruit, nor if it permits to morph into a hybrid form like normal Zoan.
Due to being a failure, it seems to have flaws. A few moments after consuming it, Momonosuke transformed automatically, and he claimed that he does not know how to revert to human form. Later he was shown to be able to accomplish the task, albeit ending up completely naked, which is unlike that of a natural Zoan. This fruit grants the general weaknesses a natural Devil Fruit would, as shown when Momonosuke could not swim.
Momonosuke originally ate the fruit on a whim to fight off hunger. He unconsciously used the ability to generate clouds to climb upwards, enough to run back up the many-stories tall garbage chute of Punk Hazard.
Momonosuke, Kin'emon's son and the dragon Luffy found in the dump.
Momonosuke in dragon form using his clouding power.
The SMILEs (SMILE（スマイル）,Sumairu?) manufactured by Donquixote Doflamingo are considered a success, and the key ingredient required to concoct the fruit is SAD, a substance that only Caesar Clown knows how to manufacture. As such, to produce such Devil Fruit requires Caesar's cooperation. The SAD is produced by Caesar, which then is transferred to the SMILE Factory in Dressrosa and processed into SMILE, and the fruits are in turn used by Kaido of the Yonko to create an army of over 500 Zoan Devil Fruit users, forming a three-way alliance. However, as they are artificial fruits, they still have their own risks, despite being a success.
Due to the Tontatta Tribe'sdwarves specializing in plants, they are forced into labor in producing SMILEs under the lie that it is medication for their sick PrincessMansherry as incentive to increase their rate of production, and the gullible dwarves believed the lie. It appears that the Tontatta can only produce only one viable fruit out of every ten SMILEs. The bottom quarter of the fruit lacks the telltale swirls, which seems to mark the difference between a successful fruit and a failure. The manufacturing process of the SMILE Factory involves having luminescent sunflowers that provide light to the trees growing the fruits, while SAD is poured into the river. The river has irrigation on both sides that channel the river under the trees to feed them.
It is unknown if this type of fruit shares any of the same weaknesses as natural Devil Fruits.
With the factory and SAD supply destroyed, and Caesar in captivity, the production of SMILE have stopped.