I remember a Sunday Family Circus panel from several years ago. The parents decided there was too much violence on TV and thought that reading to the kids would be better. They chose a book of fairy tales, not realizing how much violence was in those.
Actually, I like to think I can read it scarier than either of them! 
I don’t know why I find this one disturbing, but I do:
Hark, hark, the dogs do bark!
The beggars are coming to town!
Some in rags, and some in tags,
And one in a velvet gown.
Try the Charles Addams Mother Goose.
He makes 'em ALL oddly disturbing.
16th century and onwards? He wasn’t born until the mid 18th.
I can’t really think of a nursery rhyme that’s not vaguely disturbing when you really think about it.
Upon reading this, one rhyme popped into my head which I’ve always found bizarre.
Bat, bat, come under my hat, and I’ll give you a slice of bacon.
And when I bake, I’ll give you a cake, if I am not mistaken.
I mean, what is that, some old charm to appease the bat and stop it from biting you or something?
Never heard that version.
Milk, milk;
Lemonade;
Around the corner fudge is made.
Press the button;
Pull the chain;
Out comes a chocolate choo choo train.
And of course you do the pointing dance thing while saying it too.
{Morticia Addams]Grimm… What a lovely name.[/Morticia Addams]
Among the schoolyard rhymes we used to tell each other:
Boys go to Venus to get a new penis
Girls go to Mars to get candy bars
(Freud would have had a lot of fun with that one. Alternate version was: Girls go to Mars to get candy bars/Boys go to Jupiter to get more stupider.)
Also:
Baby, baby, suck your thumb
Wash your face with bubble gum
When that doesn’t turn out right
Wash your face with dynamite!
And:
Abraham Lincoln
I’ve been thinkin’
What the heck have you been drinkin?
Maybe juice, maybe wine
Oh my God, it’s turpentine!
During the Dan Quayle/Murphy Brown brouhaha I wrote a letter to Quayle wherein I pretended to complain that nursery rhymes and fairy tales were corrupting kids more than TV was. “What about that old woman who lived in a shoe,” I asked. I mean, she had all these kids but there was no mention of a father. And Snow White lived in a hut with 7 little men and she wasn’t married to any of them! Way to teach your kids good morals!
I got a letter from Quayle’s secretary assuring me he really did care about family values. I also got a copy of one of his speeches on the subject. It’s still lying about the house somewhere.