In folklore, every culture has its own unique death omens. These omens can be signs in nature, such as storms, or signs that occur naturally, e.g. the wax drips from a candle or coffin shapped cinders in a fireplace. Accidental happenings can also be an omen such as a chair falling over backward and a person rising from it.
Death is also foretold by the appearance of certain animals. Black birds and night birds such as rooks, ravens, owls and crows are widely regarded as death omens. When they appear in a village or lurk about a particular house, it is believed that they are warning us of someone's impending doom. The howling of a dog predicts the death of someone nearby as dogs are guardians of the underworld and guides of souls of the dead. In parts of England, if the first lamb born to a farmer is black, it predicts the death of someone in the family within the year.
Death omens also include supernatural phenomena, such as the appearance of an apparition. Another one is a phantom death coach ridden by a headless man and phantom black horses. If this phantom stops at a house, someone will die the next day. Other vehicles such as boats, cars and trains are death omens as they have come to take the souls of the dead away.
Luminous phenomena, such as corpse candles and corpse lights - bluish lights seen flickering in the night - are harbingers of death.
--- Ghosts & Spirits by Rosemary Ellen Guiley