Daemonic
Daemonic creatures are denizens of the Warp, but can manifest in real space either through sheer strength of will, hunger, or occult rituals.
Creatures with this trait increase their Toughness bonus against all damage by the number indicated in the parentheses (X), in the same manner as an Unnatural Characteristic, and stack if the latter also increases Toughness. This increase is negated by damage inflicted from force weapons, psychic powers, holy attacks, or other creatures with this trait. Daemonic creatures also have the Undying trait, and gain benefits when using psychic powers as detailed in Chapter VI: Psychic Powers.
Creatures with this trait increase their Toughness bonus against all damage by the number indicated in the parentheses (X), in the same manner as an Unnatural Characteristic, and stack if the latter also increases Toughness. This increase is negated by damage inflicted from force weapons, psychic powers, holy attacks, or other creatures with this trait. Daemonic creatures also have the Undying trait, and gain benefits when using psychic powers as detailed in Chapter VI: Psychic Powers.
Dark Heresy - Core Rulebook - 135