Whenever characters are reading from an ancient prophecy or magical spell, it will rhyme, as if every ancient scroll and tome was written by Dr. Seuss. Even funnier, the translation makes it rhyme in English, regardless of what culture it came from. It's like an attempt at Gratuitous Iambic Pentameter, running headlong into Mundane Made Awesome.
That foreign-language Prophecies Rhyme All the Time is one of the most blatant forms of either Conveniently Precise Translation (if the characters actually translate it or use Translator Microbes) or Translation Convention (if they don't). In reality, it's hard work to translate a rhyme in one language into a rhyme in the other, not the kind of thing that you could easily do on the fly.
Mind you, the translators of the classical poets like Homer, Virgil, the author of Beowulf, or Dante often find it worth the effort to make their translations rhyme. But the harder you work at something like this, the more you sacrifice things like keeping the actual meaning of the prophecy intact. And surely most prophecies are vague enough already without translating them in a way that carries their meaning even farther away from the exact events that fulfill the prophecy. In that sense, if you hear a translated prophecy that rhymes, you should be worried that it was an especially Inconveniently Imprecise translation. Remember, a poem is a toy, but a prophecy is a tool
Possibly justifiable, as rhyming when translated into the language spoken by the people who have to do something about it, and not in any language existing at the time the prophecy was written, is a clever way to prove that it's a real prophecy. But that only works if it's a sufficiently straightforward translation to show that the prophet did it rather than the translator.
The trope probably originates from the Delphic Oracle in ancient Greece, where it was standard practice for the priests attending the oracle to render her visionary ravings into elegant hexameter verse for petitioners. More generally, in pre-literate societies poetry was an important mnemonic tool - prophecies that rhyme or scan stand a far better chance of being remembered precisely than prophecies which do not, and precise wording is generally very important where prophecies are concerned.
As if to enforce the trope, some characters break out in rhyme when they receive prophetic visions.
The 4Kids dub of Ojamajo Doremi had the witches-in-training chant a rhyming couplet stating their spell's intention, rather than a string of magical words ending with a command as in the original. Amusingly, this is just what Doctor Strange does when casting spells.
Lampshaded in Issue 1 of Gold Digger, where one character translates an ancient message in rhyme, and is called on it.
Similarly lampshaded in an issue of DC's old Forgotten Realms comic, in which a character coming out of a trance and wondering what happened is laconically informed that he was just "spouting prophetic poetry. Bad prophetic poetry, at that."
Films — Animation
Lampshaded in Hercules: Hades sweet talks the Fates into telling him the future and they consent. On hearing the first few lines of the prophecy, Hades comments it.
Fates: In eighteen years, precisely, the planets will align ever so nicely... Hades:Oy, verse.
Pokémon 2000: "Disturb not the harmony of fire, ice, or lightning, lest these titans wreak destruction upon the world in which they clash. Though the water's great guardian shall arise to quell the fighting, alone his song will fail; thus the Earth shall turn to ash." Et cetera.
Mr. Beaver: When Adam's flesh and Adam's bone/Sits at Cair Paravel in throne/The evil time will be over and done. Susan: You know, that doesn't really rhyme... Mr. Beaver: You're kinda missin' the point.
Blood Sucking Pharaohs In Pittsburgh takes Egyptian hieroglyphs and achieves a rhyming prophecy in English. Then again, since the note was written by the killer, who claims she was trying to lure them in, this might not be surprising.
In Book 4 of the Lone Wolf series The Chasm of Doom, Lone Wolf can meet a mysterious old man, Gwynian the Sage of Varetta, who gives him a Scroll with an ominous prophecy foreshadowing the true nature of the threat in the book. Fortunately, this is one of those prophecies that can be foiled. Said prophecy of course rhymes.
When the full moon shines o'er the temple deep, A sacrifice will stir from sleep The legions of a long forgotten lord. When a fair royal maid on the altar dies, The dead of Maakengorge shall rise To claim their long-awaited reward.
No one who has ever had anything important to say in the Redwall books has had the ability to avoid saying it in rhyme.
In the first Artemis Fowl book, the translation of the Book of the People inexplicably rhymes.
Literary: Averted in the DragonCrown War series by Michael Stackpole. In the first, a prophecy is made in Elven, then translated into English. It doesn't rhyme in the slightest, in either language, nor was it expected to.
Perhaps one of the most famous is the Ur-quote from Lovecraft's Necronomicon: "That is not dead which can eternal lie, / And with strange aeons even death may die."
It twisted the history of and etymology of the English language so that it would rhyme.
The inscription of the One Ring: "Ash nazg durbatulūk, ash nazg gimbatul, ash nazg thrakatulūk, agh burzum-ishi krimpatul," which rhymes "find them" with "bind them," and (depending on your definition of "rhyme") "them all" with itself. "One ring to rule them all, one ring to find them, one ring to bring them all and in the darkness bind them." Considering that Tolkien was explicitly invoking the Translation Convention for his work, this suggests that it's a rhyme in at least three languages (our English, the Black Tongue, and the Westron language the notional "real" text was translated from).
Also, All that is gold does not glitter, about the return of the King (though that was more of a hopeful poem than a prophecy as such).
Ithlinne's Prophecy in Andrzej Sapkowski's The Witcher Cycle is, in its pure form, a partial example, consisting of both non-rhyming and rhyming parts. However, it is subverted and lampshaded when another character gives a concise, non-rhyming summary of this prophecy to the eponymous Witcher, who then expresses sarcastic disbelief, because all the prophecies worth the name rhyme.
The prophecy rhymes... supposedly: "When Adam's flesh and Adam's bone, Sits at Cair Paravel in throne, The evil time will be over and done." Susan calls this out in the movie ("You know, that doesn't really rhyme.").
Both prophecies, in fact: "Wrong will be right, When Aslan comes into sight, At the Sound of his roar, Sorrows will be no more, As he bares his teeth, Winter shall meet it's death, And when he shakes his mane, We shall have spring again."
Whenever a prophecy is delivered in Fool, regardless of who is delivering it, it rhymes, much to Pocket's increasing ire and bemusement.
In Steven Brust's Dragaera novels, a poem describes the Cycle of how the seventeen Houses take turns ruling the Empire. Not only does this rhyme tell what's yet to happen in future history, but what's already happened, over and over again, in the past. The Cycle turns almost entirely by natural processes (each House has genetically-determined preferences of rule and blind spots), and it's been clear what happens when for nearly two thousand centuries, so this could have sprung up later rather than being a prophecy. Comparing the English poem to what it refers to, it actually looks like a translation where some lines were changed for the sake of preserving rhyme, as some don't properly describe their House's role, or their House... or even their animal.
Lampshaded and parodied in John Moore's Heroics for Beginners. The hero meets a mysterious fortuneteller, but complains that her prophecies don't rhyme. Exasperated, she whips up a quatrain on the spot (or tries to ... she has to send him a message later with the last line).
A rare aversion in Harry Potter, no less. Twice, Professor Trelawney has delivered prophecies, neither of which exactly rhyme: Once concerning Peter Petigrew/Wormtail in Prisoner of Azkaban, and again, nearly twelve years prior concerning Harry and Voldemort.
Parodied in The Rook where the Checquy encounters many false prophecies that, "inevitably rhyme but don't scan."
Power Rangers Dino Thunder features an Egyptian curse in rhyming English. The tablet with the cryptic solution also proves to rhyme in English.
Averted in Buffy the Vampire Slayer and Angel. Prophecies are not unusual in either show, but they rarely rhyme; indeed, they're usually just a line or two of prose.
Demons run when a good man goes to war. Night will fall and drown the sun When a good man goes to war. Friendship dies and true love lies, Night will fall and the dark will rise, When a good man goes to war. Demons run, but count the cost; The battle's won, but the child is lost.
Star Trek: Deep Space Nine. Averted with Bajoran prophecies, with the notable exception of Horran's Seventh which begins, "He will come to the palace, bearing no malice, carrying a chalice, filled with sweet spring wine."
In Once Upon a Mattress, both the Marriage Law and the curse on King Sextimus are stated as rhyming couplets.
Quest For Glory I has the following prophecy, which does outline what you need to do through the game:
Comes a hero from the east Frees the man from the beast Brings the child out from the band Drives the evil from the land
Quest for Glory II also has a rhyming prophecy. Interestingly, there are two translations of the prophecy, with totally different meanings, and they both rhyme.
To find the treasure of yore take the seven Crystal Stars to the Thousand-Year Door. Hold the Magical Map aloft before the entrance to the Thousand-Year Door. Then the stars will light the way that leads to the stones of yesterday.
Averted in Digger, where they may not even be a complete sentence.
In Rusty and Co., Madeline's quest hooks, courtesy of Derek the Cleric.
Teen Titans: "The Gem was born of evil's fire;/the Gem shall be His portal./He comes to claim, He comes to sire/The end of all things mortal."
It also happens in one episode of Kim Possible when Kim is trying to protect a young prince from the descendants of the Royal Families treacherous knights: "Awaiting the light of a full harvest moon;/Rodigahn's foe will soon face his doom/In the shadow of the palace we will not be deterred;/the monarchy ends with Wallace The Third."
Parodied in a live-action segment in the The Super Mario Bros. Super Show. Luigi made his brother disappear. The spell to bring him back (according to the Guest Star) was something like "Ping-ping pear... wing-wing wear... make old Mario... Re-a-pear!"
Very few people know that the prophecies of Nostradamus rhyme in French, because they definitely do not in English. Note that Nostradamus' French is archaic and barely counts as French, even for its time. It's one of the reasons that people can so easily lend meanings to his words.
While ancient Greeks generally didn't use rhymes, the prophecies issued e. g. by the Oracle of Delphi frequently took the shape of verse.