Via a comment at Language Hat (FOUR MORE YEARS!), I bring you a bunch of Japanese translations of Jabberwocky, kindly posted by Adam Rice.

I had seen one attempt at a Japanese Jabberwocky translation before, but it was just a straight rendering into flat, modern Japanese, with all of Carroll's nonsense words transliterated into katakana. Sadly, without the context of English (and its poetic tradition), the words lose all their power. It was the literary equivalent of a fake airstrip laboriously constructed out of coconuts.

The ones Adam has posted are generally much better, because the translators understand the idea, and use all the resources at their command to recreate not Jabberwocky itself, but what Jabberwocky would have been if Carroll had been Japanese.

So, for instance, most of them write in a pastiche of classical Japanese, with as many archaic verb endings and conjugations of beshi as possible. Some of them draw on the tradition of ateji, i.e. assigning Chinese characters to a word they have no historical or etymological association with. The word "Jabberwocky", for instance, is variously rendered as 邪婆有尾鬼 (wicked hag has-tail devil), 蛇馬魚鬼 (snake horse fish devil), etc., all pronounced as a reasonable Sino-Japanese approximation of the original English word.*

And, of course, morphemes are abused. "Slithy", for instance, gets translated into faithfully evocative nonsense like shinebai (shinayaka (lithe) + nebai (sticky)?) or nuranayaka (nuranura (sticky) + shinayaka?)... and so on.

My favorite of the lot is TAKAYAMA Hiroshi's, apparently from a 1980 translation of the Annotated Alice, which starts like this:

ゆうまだきにぞ ぬめぬらとおぶ
  にひろのちにや ころかしきりる
うたてこばれたるぼろこおぶ
  えかりたるらあすぞひせぶる