The Pacifista are human weapons developed by Marine head scientist, Dr. Vegapunk. They are cyborgs built in the mold of the Seven Warlords of the Sea Bartholomew Kuma, who was the cyborg prototype for the project. As stated by Sentomaru, the funds required for the construction of just one Pacifista are roughly equal to that of a Marine-issued battleship.
Sentomaru noted that after the timeskip period, PX-5 and PX-7 were outdated models from two years ago, meaning that the Pacifista project has been updated and modified.
All the Pacifista replicas seen thus far have been identical in appearance to Bartholomew Kuma, even in his uncommon body proportion. The only distinguishing features between them and the genuine article are the lack of a Bible and Kuma's Paw-Paw Fruit palm pads, though the latter is not initially apparent as they all wear similar gloves. The Pacifista are built from human corpses, except for the original Kuma, who was gradually converted into a Pacifista. The Pacifista have the voice of Kuma, furthering their genuine replication to him. They all have no memories of their past lives and are under complete control of the World Government.
Their appearances are so convincing that pirates unfamiliar with the genuine article believe they are the real Kuma. The Straw Hat Pirates, having previously fought Kuma, were able to tell the difference eventually. Likewise, X Drake, a former rear admiral familiar with the project, was aware of its nature. Some New World pirates are aware of Vegapunk's experiments, and that he sent several prototypes to handle incidents in the past, but were surprised that they were all modeled after Kuma.
All Pacifista are labeled by the letters "PX", then a hyphen and a number, presumably indicating the order in which they were constructed. The label is printed on the right side of their necks. There appears to be around twenty of them in service as of the Marineford War, though it is unknown how many have been destroyed and built since then.
Pacifista are straightforward and robotic in the execution of their duties. They can identify pirates with active bounties and will immediately attack. Pacifista will normally avoid attacking allies, such as the Shichibukai, though this directive can be ignored if they are ordered to attack. If they are not ordered to, they will not even attack when they are attacked themselves, as seen when Hancock destroyed several Pacifista in a row. It is not clear exactly what command structure the Pacifistas fall under. At the very least, they will obey Sentomaru and Kuma himself.