We've had some threads around this but this oughta' be good to see if we can get a bunch on one thread. Here are two based on "God Rest Ye Merry Gentlemen:"

THE RESTROOM DOOR SAID 'GENTLEMEN'
from Bob Rivers' "Twisted Christmas"

The restroom door said 'Gentlemen'
so I just walked inside.
I took two steps and realized
I'd been taken for a ride.
I heard high voices, turned and found
the place was occupied
by three nuns, two old ladies and a nurse.
What could be worse
than three nuns, two old ladies and a nurse?


The restroom door said 'Gentlemen'
it must have been a gag.
As soon as I walked in there,
I ran into some old hag.
She sprayed me with a can of mace
and hit me with her bag.
It just wasn't turning out to be my day.
What can I say?
It just wasn't turning out to be my day!


The restroom door said 'Gentlemen'
and I would like to find
the crummy little creep
who had the nerve to switch the sign.
Because I've got two black eyes
and one high heel up my behind.
Now I'll never sit in comfort or joy.
Boy oh boy!
Now I'll never sit in comfort or joy.


OR this one....a catspaw original......

The Miserable Tailor
from the twisted mind of catspaw

God damn you Harry Mendelson
These pants are much too short
The cuffs don't cover up my socks
I'm sorry to report
The belt loops they are all in back
The crotch is at my knees
What a miserable tailor are you
You sunnavabitch
What a miserable tailor are you!


God damn you Harry Mendelson
This vest's a total wreck
You've cut it wrong its plain to see
It buttons to my neck!
The fourteen buttons don't line up
With eleven buttonholes
What a miserable tailor are you
You sunnavabitch
What a miserable tailor are you


God damn you Harry Mendelson
The coat is all wrong too
One lapel is bright red plaid
The other pinstripe blue
The left sleeve covers up my hand
The right one isn't there
What a miserable tailor are you
You sunnavabitch
What a miserable tailor are you

Then you can check out this thread on Jingle Bells for some parodies there.

Also, not to be forgotten is the following to "Winter Wonderland:"

WALKIN' ROUND IN WOMEN'S UNDERWEAR
(Bob Rivers)

Lacy things -- the wife is missin',
Didn't ask -- her permission,
I'm wearin' her clothes,
Her silk pantyhose,
Walkin' 'round in women's underwear.

In the store -- there's a teddy,
Little straps -- like spaghetti,
It holds me so tight,
Like handcuffs at night,
Walkin' 'round in women's underwear.

In the office there's a guy named Melvin,
He pretends that I am Murphy Brown.
He'll say, "Are you ready?" I'll say,"Whoa, Man!"
"Let's wait until our wives are out of town!"

Later on, if you wanna,
We can dress -- like Madonna,
Put on some eyeshade,
And join the parade,
Walkin' 'round in women's underwear!

Lacy things... missin',
Didn't ask... permission,
Wearin' her clothes,
Her silk pantyhose,
Walkin' 'round in women's underwear,
Walkin' 'round in women's underwear,
Walkin' 'round in women's underwear!


I'm sure some additional things will be showing up soon.

Spaw