I don't know why you expect to be different from all the other parents, we all desparately make up words.
I use ... if that Billy Goat runs away, daddy's going to get you a horse and sleigh.
If that horse and sleigh turns over daddy's going to get you a dog named Rover.
If that dog named Rover won't bark, daddy will get you a meadowlark.
then I start getting desparate.
There was a parody done by the Brothers In Law in the sixties called 'Lullaby to a Spoined Brat' does anyone have the lyrics to that?