The Umbra is a spirit related to shadow people or the lethifold. An umbra is a creeping, living shadow. It uses fear to manipulate people and feeds off of the energy of their fear. I came across the story of a minister in the 1700's capturing one in a jar and displaying it to some school children. The entry in his journal tells how it swirled around in the jar and seemed to have some form. They are semi-gaseous, and because of this can be captured in a sealed container. The best defense against the umbra is your basic holy water, salt and light. Because they are creatures of shadow, these are the greatest defenses.