Here is a contribution that goes back to the Nineteenth Century. You can tell it's from a British source because of the word sods (sodomites). The storming of the Khyber Pass is a reference to the Second Afghan War (1878-1880), in which the entire British occupying force was wiped out except for one man. Only the first two stanzas were on the web, and the words poorhouse and warden were workhouse and master. Christmas pudding is also called plum pudding.
I'll sign it here so that it's clear I'm not claiming authorship.
Joe Tamargo
CHRISTMAS PUDDING
It was Christmas in the poorhouse,
The best time of the year;
And the paupers all were happy,
For their guts were full of beer.
In strode the poorhouse warden
And peered into their stalls.
He wished them all a Merry Christmas,
And the paupers answered "Balls."
The warden did not like this,
And he shouted "By the Gods!
You shall have no Christmas Pudding,
You ungrateful lot of sods."
Up spoke a grizzled veteran,
Who had stormed the Khyber Pass:
"We don't want your Christmas Pudding,
You can shove it up your ass."