The Witcher Bestiary - Barghest
Barghest Occurrence: Barghests are ghosts which come from the underworld only when summoned.

Immunity: Barghests are fearless and cannot be poisoned; coming from the underworld they acquire bodies, so they can be stunned and experience pain, although they are somewhat resistant to these effects.

Susceptibility: Barghests are sensitive to silver and very susceptible to knockdown attempts; the Fast Style is most efficient against barghests and experienced witchers use the Group Style while fighting multiple barghests.

Tactics: They try to surround their opponent and work as a group where one barghest appears, more will follow.

Alchemy: Beast fangs, ectoplasm, and Death Dust.

People say that barghests are specters which materialize as ghastly dogs and persecute the living. According to some folk tales these monsters are the scouts of the Wild Hunt. Other legends say the ghosts appear as a sign of divine retribution and embody revenge. However, all tales agree on one point: barghests show the living no mercy.