Merry Christmas, your last one

Twas the night before Yuletide and all through the hole
Not a creature was stirring, not even a Dhole
Aldebaren hung at the right place at nine
In the hopes that Great Cthulhu would come out this time

The Fungi from Yuggoth, all snug in their caves
Were plotting to turn all the people to slaves
The Deep Ones in Rlyeh, the Ghouls in their graves
Were dancing and singing and acting depraved

When what do my wondering eyes should appear
But a mouldering sleigh and eight corpselike reindeer
With a horrible driver so leprous and reeking
I knew right away that my fear was unspeaking

The reindeer were gross, as they flew up from hell
And It hoarsely whispered and chanted a spell
Ia Shub Niggurath! Cthulhu ftagn!
Nyarlathotep! I summon you on!

As decomposed flesh before the charnel stench rise
And meet with the open air polluting the skies
Up to the housetop the horror it rose
And the gangrenous odors assailed my nose

And then in a slopping noise heard on the roof
The lumbering clomping of octopoid hoofs
As I drew in my head and was turning around
The horror lurched into my room with a bound

Its eyes how they pulsate
So bulbous and gory
This blasphemous creature
So noxious and hoary

I was frozen by fear, my feet woudn't run
I threw up my cookies, this wasn't much fun
It whispered my name and said "You come with I"
I tried to refuse and it said "Then you die."

It came at my throat with its grim claws extended
But a miracle saved its victim intended
I had three Elder Signs in a slot in the floor
It screamed with a fiendish sound and went out the door

It sprang to its sleigh, and its team gave a surge
And away they all flew to the sound of a dirge
I heard it exclaim as it flew out of sight
"You're lucky this time, for the stars weren't right."

This joke gets old quickly, but there's always the first time you hear it...