“Rudolph the Red-Nosed Reindeer” in Anglo-Saxon meter, by Philip Craig Chapman-Bell. Via Etymonline on Facebook, who says “An Internet classic; but I can no longer find it where I first found it (Cathy Ball’s Old English reference pages).”I was delighted when I first read this that it really is following Old-English rules of poetry, which didn't expect rhymes like modern English poetry but rather Anglo-Saxon meter, which has alliteration rather than rhyme and uses a lot of compound nouns (known as kennings).
Incipit gestis Rudolphi rangifer tarandus
Hwæt, Hrodulf readnosa hrandeor –Rendered literally into modern English:
Næfde þæt nieten unsciende næsðyrlas!
Glitenode and gladode godlice nosgrisele.
Ða hofberendas mid huscwordum hine gehefigodon;
Nolden þa geneatas Hrodulf næftig
To gomene hraniscum geador ætsomne.
Þa in Cristesmæsseæfne stormigum clommum,
Halga Claus þæt gemunde to him maðelode:
“Neahfreond nihteage nosubeorhtende!
Min hroden hrædwæn gelæd ðu, Hrodulf!”
Ða gelufodon hira laddeor þa lyftflogan –
Wæs glædnes and gliwdream; hornede sum gegieddode
“Hwæt, Hrodulf readnosa hrandeor,
Brad springð þin blæd: breme eart þu!”
Here begins the deeds of Rudolph, Tundra-Wanderer
Lo, Hrodulf the red-nosed reindeer –
That beast didn’t have unshiny nostrils!
The goodly nose-cartilage glittered and glowed.
The hoof-bearers taunted him with proud words;
The comrades wouldn’t allow wretched Hrodulf
To join the reindeer games.
Then, on Christmas Eve bound in storms
Santa Claus remembered that, spoke formally to him:
“Dear night-sighted friend, nose-bright one!
You, Hrodulf, shall lead my adorned rapid-wagon!”
Then the sky-flyers praised their lead-deer –
There was gladness and music; one of the horned ones sang
“Lo, Hrodulf the red-nosed reindeer,
Your fame spreads broadly, you are renowned!”
My (sadly never finished, thanks nervous breakdown!) senior-seminar in college was about Old English riddles, which meant I had to read and write so much about kennings, clever/poetic ways of describing things (like "hoof-bearers" or "sky-flyers" in this). Often, it seems these clever constructions were not intended as solely poetic, artistic turns of phrase but created in order to keep to the rules about alliteration. Even if you don't know how the Old English is supposed to sound, you can probably see the alliteration in most of the lines about good old Hrudolf here.
From the same website, All Things Linguistic, where I learned about Hrodulf readnosa hrandeor, I also recently discovered the existence of the History of English podcast which goes into all this stuff in so much detail it's about thirty episodes before you get to anything recognizably English at all. I'm used to the history of English beginning after the Romans left Britain, and this is so much better, going all the way back to Proto-Indo-European and covering thousands of years of linguistic development as it affects English. It might be too detailed for a lots of people but I'm absolutely loving it.