Portent of Doom

The writing on the wall. A mystical phenomenon that tells of a dire future for those who witness it.

Compare to Foreshadowing, the out-of-universe equivalent.

Only place examples here that do not belong on one of the subtropes.

Film - Animated

 * In Tales From Earthsea, the sightings of dragons fighting is taken to be a sign that the balance of the world is greatly upset, perhaps irreparably.

Film - Live Action

 * In Practical Magic, the chirping of the death watch beetle foretells the death of a loved one.
 * Darby O'Gill and the Little People had a banshee (evil spirit) that appeared and wailed mournfully when someone was about to die.

Literature

 * In the first few chapters of Romance of the Three Kingdoms, the end of the Han dynasty is seen in some very bad portents (a horrible plague among one of those things), kicking of the chain of events that leads to decades of war.
 * I Heard The Owl Call My Name, in which the protagonist is subjected to the named portent of death (and in this case survives, as it's autobiography.)

Myth, Legend, and Religion

 * In the book of Daniel, supernatural writing foretells the demise of the Babylonian Empire. It is the origin of the phrase "the writing on the wall."
 * The phrase written, Mene, mene, tekel, u-Pharsin and its translations "numbered, numbered, weighed, and divided" (figuratively) and "You have been judged and found wanting [by God/the Persians (unwittingly acting for God)]" are also used.

Theatre

 * In Julius Caesar Portia urges Caesar not to go to the Senate because of the various omens she's either witnessed or heard about from reliable sources. Caesar poo-poos it and goes anyway.