This parody was posted on the groaners listserv

On the first night of Halloween My true love gave to me… A vulture
in a dead tree!

On the second night of Halloween My true love gave to me… Two
flying bats And a vulture in a dead tree!

On the third night of Halloween My true love gave to me… Three
black cats, Two flying bats, And a vulture in a dead tree!

On the fourth night of Halloween My true love gave to me… Four
hooting owls, Three black cats, Two flying bats, And a vulture in a
dead tree!

On the fifth night of Halloween My true love gave to me… Five TRICK-
OR-TREATS, Four hooting owls, Three black cats, Two flying bats, And
a vulture in a dead tree!

On the sixth night of Halloween My true love gave to me… Six ghosts
a-haunting, Five TRICK-OR-TREATS, Four hooting owls, Three black
cats, Two flying bats, And a vulture in a dead tree!

On the seventh night of Halloween My true love gave to me… Seven
doors a-creaking, Six ghosts a-haunting, Five TRICK-OR-TREATS, Four
hooting owls, Three black cats, Two flying bats, And a vulture in a
dead tree!

On the eighth night of Halloween My true love gave to me… Eight
vampires biting, Seven doors a-creaking, Six ghosts a-haunting, Five
TRICK-OR-TREATS, Four hooting owls, Three black cats, Two flying
bats, And a vulture in a dead tree!

On the ninth night of Halloween My true love gave to me… Nine
monsters howling, Eight vampires biting, Seven doors a-creaking, Six
ghosts a-haunting, Five TRICK-OR-TREATS, Four hooting owls, Three
black cats, Two flying bats, And a vulture in a dead tree!

On the tenth night of Halloween My true love gave to me… Ten
spiders spinning, Nine monsters howling, Eight vampires biting, Seven
doors a-creaking, Six ghosts a-haunting, Five TRICK-OR-TREATS, Four
hooting owls, Three black cats, Two flying bats, And a vulture in a
dead tree!

On the eleventh night of Halloween My true love gave to me… Eleven
witches brewing, Ten spiders spinning, Nine monsters howling, Eight
vampires biting, Seven doors a-creaking, Six ghosts a-haunting, Five
TRICK-OR-TREATS, Four hooting owls, Three black cats, Two flying
bats, And a vulture in a dead tree!

On the twelfth night of Halloween My true love gave to me… Twelve
pumpkins grinning, Eleven witches brewing, Ten spiders spinning, Nine
monsters howling, Eight vampires biting, Seven doors a-creaking, Six
ghosts a-haunting, Five TRICK-OR-TREATS, Four hooting owls, Three
black cats, Two flying bats, And a vulture in a dead tree!

and from Bill Stebbins this alternate version:

On the twelfth day of Halloween,

My good friend gave to me,

Twelve cauldrons bubbling,

Eleven bats a swooping,

Ten goblins gobbling,

Nine wizards whizzing,

Eight brooms a flying,

Seven spiders creeping,

Six owls a screeching,

Five cooked worms,

Four giggling ghosts,

three fat toads,

Two hissing cats,

And a vulture in a dead tree.