Rasklapanje is a victim of the C-Virus, although one that is extremely mutated. Rasklapanje is derived from the Serbian word for "dismantle." 
This dangerous leech-like B.O.W. was encountered by Ada Wong in Lanshiang during the bioterror incident, wandering in an abandoned aircraft carrier. The same ones were later encountered by Chris and Piers. Another was fought by Leon and Helena in the city's back alleys. It is also encountered by Jake Muller and Sherry Birkin in the underwater facility where they were imprisoned. Its Serbian name means "dismantle" which is a play on its ability to detach its body parts.
Below is a memo written by a Neo Umbrella researcher.
We've had a very irregular mutation occur in some of our subjects. The resulting creature is able to separate parts of its body and send them after its victim. Its body parts seem to have a mind of their own as they search and attack, but once they return to the main body, they all go back to working as one.
We still have a lot to learn about this mutation, but it will most certainly be an effective weapon in the field.
Lanshiang Bio-terrorist Attack
Several of these creatures appeared in various locations in Lanshiang;
One was encountered by Leon and Helena within a meat market in the city's back alleys, where it was already torn to pieces in a pile of garbage. The creature demonstrated its regeneration ability, quickly "reassembling" its limbs. This Rasklapanje would chase Leon and Helena throughout the meat market as they attempt to find three keys to open the barricaded gate of a butcher shop. Another will emerge from the wall grating when the key behind the electrified door is picked up.
After successfully breaking into the butcher shop, another Rasklapanje was fed into a giant meat grinder by Leon/Helena, destroying its body entirely.
As Ada was exploring an abandoned aircraft carrier off the shores of Tatchi, she found a security door requiring 3 passcodes. As she began searching, she encountered multiple Rasklapanje as well as J'avo. After acquiring all the passcodes with her communicator cube, she proceeded to encounter more of the B.O.W.'s which she was able to escape from with her grappling gun.
Chris and Piers encountered the same group of Rasklapanje as Ada when they explored the same aircraft carrier. The group of Rasklapanje would stalk Chris and Piers throughout the ship as they attempted to collect the passcodes Ada had left behind with the corpses of the J'avo she had killed to acquire them. After finding all the codes and bypassing the secured door, the creatures burst through a ventilation grate, where they were blown by combined gunfire from Chris and Piers into a smelting pit, incinerating them.
Another Rasklapanje was found wandering the undersea oil field where Sherry and Jake were held by Neo-Umbrella. This one pursued the pair as they tried to restore power to an elevator in order to escape the facility. Jake would eventually send it falling onto an electric fence, where it was momentarily incapacitated by the high voltage, causing the facility to overload. It was eventually crushed by the malfunctioning elevator.
?, ed (2012). BIOHAZARD 6 Official Complete Guide. Famitsu.