When I was little, living in Toronto, I remember watching this cartoon that always stuck with me. It was KIND of like the Twiligh Zone in that it had a narrator/host and it told urban legends, which were often cautionary tales.

The one I saw was about a teenage girl who wanted to look gorgeous, but was also very lazy. So instead of taking proper care of her hair, she just engulfed it in hairspray every day. Then one day her head began to hurt, so she went to the doctor, and her hair was so hard, he had to slice it open with a chainsaw (this is a cartoon remember) and when he did that, they discovered that her hair was hollow. Inside, tiny baby spiders had eaten it out and they all came falling out of the top of her hair.

I know it sounds weird, but I loved the creepiness factor of the show, and I especially loved the fact that it was a cartoon.

I'll tell you this-- it wasn't Tales from the Crypt cartoon which my description kind of sounds like. So you've got that eliminated. Any other guesses?