There is mention of a skin grinder in the pirate arc. This is played for laughs in the story, but this means that there apparently was an actual skin grinder (with a legend) living on the island they were on, inside of the cave they were in. Jack Sparrow had also seemingly been in that cave a lot longer, particularly since he had treasure inside. Luck doesn't even begin to cover how he never got attacked.
It may seem funny at first, but all signs in chapter 73 point to the possibility that Winthorpe was actually going to rape Ciel.
Back in chapter 30, Ciel goes on a long and nonsensical rant where he says quite a few things that aren't quite understandable. If you really think about it though, in one line he says he's going to sneak up on Lettuce while she sleeps and turn her into a vampire. In front of her.
"So chuckie put his swiord down to give otachi the disease and otachi didn't feel too well. He turned pale"
This sounds funny, but... what disease? The more you read it, the creepier it gets.
It's worse when you learn that the "disease" sets Otachi's ears on fire (which could be a joke) and causes him to throw up his intestines.
Otachi getting back Winthorpe's body piece-by-piece in chapter 70. He starts with a leg, then the other leg, then an arm, then another (mysteriously acquiring the torso along the way), and then the head.
The fact that snails live in Mew Waterfall's hair is kind of disturbing.