This tale can be interpreted on a few levels that intertwine. First, it is a classic beast fable that intends to teach the lessons of being aware of flatterer's intentions and heeding the warnings of dreams through animal characters. Second, it is a mock epic which reduces the regalia of the high epic adventures of knights to a lowly barnyard scene. All of this is revealed through the voice of a priest whose job is to serve a high ranking nun.
The mock-hero Chanticleer's dreams of dying are teased and dismissed by his mock-damsel hen Pertelote. Yet, they are revealed to be correct by the invasion of the mock-villain Sir Fox. Here we find an example of what can be called misogynistic swayings in that the female is able to convince the male to ignore his gut instincts. This might be indicative of a male teller who finds himself in the position of having to serve a woman in a time when that arrangement is extremeley rare.
When Chanticleer is captured by the Sir Fox, the ensuing chase scene is not epic but comical, serving the purpose of the mock epic.
Many of the most famous Canterbury Tales by Geoffrey Chaucer deal with the dynamics of marriage, and here we have a hen-pecked husband. When he tells his beloved Pertelote that he dreamed he was attacked by a "yelow and reed" beast (a fox), his wife questions his manhood (should I say roosterhood?) much as Lady Macbeth questions Macbeth's in order to prod him into killing King Duncan. "Now han ye lost myn herte and al my love, I kan nat love a coward, by my feith! For certes, what so any womman seith, we alle desiren, if it myghte bee, to han housbondes hardy, wise, and free, and secree, and no nyugard, ne no fool. . . .How dorste ye seyn, for shame, unto youre love that any thyng myghte make yow aferd?"
Pertelote not only questions the idea of her husband being afraid of anything, she is particularly put off that he should be afraid of a dream. "Allas! and konne ye been agast of swevenys [dreams or visions]? Nothyng, god woot, but vanitee in sweven is." And here is where it begins to get fun: first she quotes an ancient authority, Cato, as saying dreams have no meaning. Chaucer is mocking the medieval penchant for basing most arguments upon the precedents set by ancient authors or authorities. (Note: the Wife of Bath begins her story by comparing her personal experience against the dictums of the authorities.) Pertelote next puts forward a rational, scientific explanation for the source of dreams, complete with illustrations. Dreams come from overeating, she asserts, which throw the body's "humours" out of balance. Thus the dream of a red beast comes from an overabundance of Chanticleer's "reed colera" which causes people to have nightmares of arrows, of fire with red flames, and of red beasts that bite. She continues to describe imbalances of another humour, melancholy, the black humour that leads to dreams of black bears or bulls or black devils.
Now, having a physical cause for his dream, Pertelote prescribes a physical cure: eating the proper herbs will fix him right up! For convenience, I will use David Wright's translation from the 3 volume Folio Society Dual Language edition (1985).
Now sir...take...some laxative...purge yourself of the red choler and black melancholy. To save time, as there's no apothecary here to be had, I'll be your guide myself and show you herbs to benefit your health; and in our own yard I shall find hose herbs which have a natural property to purge from top to bottom, above and beneath... (197)
Chanticleer's response is the first to challenge Pertelote's reference to Cato by citing a greater authority, Cicero, who he says tells a story of two friends who set out on a pilgrimage, only to have one of them murdered while the two are separated. It's worth noting that we now have a story in a story in a story, for the Nun's Priest's Tale began with a tale of a poor widow, shifted to the story of her rooster's bad dream, and now the rooster is telling his mate a third story, which will be followed by a fourth with other examples before the rooster's own adventures continue. But in essence, the Cicero story tells of how one friend was visited by his missing friend in a dream, who warned him to come quickly, for he was about to be murdered. This repeats a few times until the forlorn ghost appears in the dream to say too late! But he tells where his body can be found. And of course, it all turns out to be true; the dream vision was not meaningless nonsense, but a true warning of what was about to happen. I also must point out that the tale contains the expression, "Mordre wol out"--or Murder will out, which most people attribute to Shakespeare's Macbeth, but appears here in Chaucer two centuries earlier! In any case, the tale presents this conflict: dreams are nonsensical responses to physical disorders in the body and can be cured with the proper medicines or foods versus dreams are important visions from the spiritual realm that can warn us of what is to come. It's interesting to note that the stereotypical roles are reversed—some might expect the male to be the voice of science and reason and the woman to represent more spiritual, mysterious thinking.
Well, the rooster listens to his wife and ignores his dreams warnings. Therefore he is nabbed by the fox, who as noted in the previous answer, uses flattery to seduce Chanticleer into closing his eyes long enough for the fox to nab him, only to be tricked in turn by the poor rooster, who fools the fox into opening his mouth to taunt the widow and her family who are pursuing them--giving Chanticleer a chance to fly up into a tree. The fox tries flattery again, trying to coax the rooster down, but the rooster will not be fooled twice. Thus, the latter portion of the tale does reflect a moral about not trusting flatterers, but there is also this moral, provided in Latin by Chanticleer himself: "In principio Mulier est hominis confusio," which the rooster wrongly translates to mean woman is man's joy and all his bliss. The astute reader, however, need not know much Latin to discern that the true meaning is: principally, woman is man's confusion (ruin). Thus a second moral emphasized in the tale is don't let women lead you astray.