The Farfarello (lit. Slanderer, elf, goblin, or evil spirit; named after one of the thirteen devils named the Malebranche from the Divine Comedy) is an independently improved species of the HunterB.O.W.
Farfarello were developed at some point prior to the Queen Zenobia Incident, created through infecting Hunters with t-Abyss Virus. In 2005, BSAA chief Clive R. O'Brian provided a pack of Farfarello for Il Veltro, a small paramilitary named after the 2004 Italian movement. The group lost control of their pack at their base in Valkoinen Mökki Airport, resulting in a plane crash and the loss of all ground forces. This also resulted in the crashing of a cargo plane that Chris Redfield witnessed, due to one of the Farfarello being sucked into the engine while it was attacking it. Later on, the Farfarello were encountered by BSAA officers dispatched to the area.
A file found near the crash site implied that these Hunters were intended to be a prototype B.O.W. that could be controlled while being administered prescribed sedatives. It also stated that these B.O.W.s were unpredictable and impossible to control without hourly sedation. During the transporting of the Farfarello's, their sedatives had worn off, explaining their attack on Il Veltro's base and aircraft.
Following Quint Cetcham's data mine of an II Veltro computer terminal and discovered incriminating evidence against Morgan Lansdale of the FBC, Morgan Lansdale ordered an airstrike bombing of the base. The airstrike bombing destroyed the entire facility and any B.O.W.s present.