Jabberwocky

A nonsense poem by Lewis Carroll, supposedly written deliberately for the purpose of mocking poorly-written nonsensical poems. Of course, since it's Lewis Carroll, it is considered an excellent poem despite this nonsensicality. It is said to have been inspired by a tree. Make of that what you will.

Inspired a Terry Gilliam film of the same name.

The poem contains examples of:

 * Absurdly Sharp Blade: The Vorpal Sword.
 * Achilles in His Tent: Briefly. The Hero stops to rest by a tree, and then stands there for a while in "uffish thought" (basically, sulking).
 * All There in the Manual: Carroll created definitions for his nonsense words.
 * Audible Sharpness: "The vorpal blade went snicker-snack!"
 * Big Bad: The Jabberwock.
 * Book Ends: The first and last stanzas are identical.
 * Losing Your Head: How the Jabberwock dies.
 * Makes Just as Much Sense in Context: Unless you've read Carroll's definitions...
 * No Name Given: Neither The Hero nor his father are mentioned by name.
 * Perfectly Cromulent Word: Carroll filled his poem with words that did not exist at the time (burbled, vorpal, tulgy...)
 * Defictionalization: Some of these words, such as "chortled", are now in the Oxford English Dictionary.
 * 24-Hour Trope Clock: Brillig is four o'clock in the afternoon, just when you start to broil things for dinner.
 * "Well Done, Son" Guy: "And hast thou slain the Jabberwock? Come to my arms, my beamish boy!"

The movie contains examples of:

 * Dolled-Up Installment: It was released in some areas as Monty Python's Jabberwocky, despite half of the group having no involvement.
 * Although Neil Innes, sometimes called the seventh Python, does appear.
 * Too Dumb to Live: When the king discovers that his land is threatened by the Jabberwock, he holds a contest to find the strongest knight in the land, by having all the knights battle each other to the death. Simply putting all his knights together into a single army, with all of them alive, apparently just wasn't done back then.

Elements of this poem appear in:

 * Dungeons and Dragons: The sword +5, vorpal weapon derives its name from the poem's vorpal sword. In D&D, such a weapon automatically decapitates its target on a critical hit/natural 20.
 * In the short story "Mimsy Were the Borogoves" by Henry Kuttner and C. L. Moore (writing under the joint pseudonym of Lewis Padgett), the poem turns out to have been dictated by Lewis Caroll's young daughter after she received some Sufficiently Advanced toys from the far future, and is a secretly-coded instruction manual for how to Ascend to a Higher Plane of Existence.
 * Larry Niven's Known Space universe has an alien species called the frumious bandersnatch.
 * The Jabbewock is a kind of monster -- one of the most powerful in the game -- found in the original Rogue.