I don't have time to write it right now, but how about a parody on "Way Down Yonder in the Paw Paw Patch," called --what else but "Way Down Yonder in the Pumpkin Patch?" (The words to the original song are here in a forum thread.)

Genie Here's one to "Baby Face:"

Pumpkin Head, you've got the scariest little pumpkin head,
With nose of carrot and two eyes of red, Pumpkin Head,
My poor heart's a-beatin!--
It's time for trick-or-treatin'!
Pumpkin Head, I love to see you glowin' like the living dead!
Bring on the zombie scene!
It's time for Halloween
And your ghoulish pumpkin head!