Body bag in a dream: what does it mean?
One of the bleakest dream objects there is, and its meaning is rarely obscure: the dream has supplied the fact of a death and removed the person.
How do the four traditions read it?
Each reading below comes from a named tradition and a cited source, so you can see where it came from and decide what fits your dream. The four often disagree, and that is the point: a symbol rarely means one fixed thing, and the distance between Freud, Jung, modern research and myth tells you more than any single verdict could.
Freud
Freud would attend to the concealment, since a dream that supplies a body and hides it has arranged both the fact and the refusal to look. He would ask whether the dreamer knew who it was.
After Freud, The Interpretation of Dreams (Brill trans., 1913), public domain.Jung
For Jung the anonymous container can image a death the dreamer has not been permitted to make personal, and the not-knowing is frequently the more distressing half of the dream.
Our summary of a Jungian reading, in our own words, not Jung's. See Jung, ed., Man and His Symbols (1964).Modern
Under the continuity view these tend to follow real bereavement, real news coverage and real work in emergency services. For anyone in those jobs the dream is occupational rather than symbolic, and is well documented.
Our summary of the continuity hypothesis, named by Calvin Hall and Vernon Nordby, The Individual and His Dreams (1972). Its correct scope is disputed; see Domhoff (2017) and the replies to him.Mythological
Traditions place heavy obligations on the treatment and identification of a body, and the anonymous bag runs against nearly all of them, which is a large part of why it is so disturbing as an image.
Rosmerta Publishing editorial synthesis (after Frazer; Bulfinch).How can writers use this symbol?
The same symbol, read as craft material rather than as a dream. What it does on the page, how genres use it differently, and what happens when you turn it inside out. Written for novelists, screenwriters and poets who need the symbol to actually work, and it ends with something to try.
In literature
War and emergency writing use this object carefully or not at all, and the difference between the two is usually whether the writer has been near one.
Rosmerta Publishing editorial synthesis. Our own words; no quoted text.What it does in a story
It converts a person into a logistic, which is exactly the horror worth writing. Structurally it is a full stop: there is nothing to be done with it and no scene after it except grief.
Genre conventions
War fiction uses the count. Crime uses the removal. Literary fiction uses the family watching it happen, which is the only version that is about anything other than the object.
How to subvert it
Write the person whose job it is, doing it with care, and give the whole scene to the care.
Try this
Write a hospital corridor at four in the morning. Something is being wheeled past. Two hundred words.
Only the first of these names a source. What a symbol does in a story, how genres treat it, how to invert it and what to try are our editorial judgement as writers and editors, not findings from a body of research. They are offered as craft opinion and should be argued with.