I'm trying to not do too many Harry Potter names because 1) my fandom can get out of hand and I want to talk about other books and 2) I can always go crazy when the last movie comes out. But I do have room for one name for the party.
So let's say that you're a little macabre and very pregnant (oh, come on, I know you're out there), and you love the Voldemort character. Voldemort is obviously too much for a baby, and Tom is too ordinary...would you consider Riddle?
When J.K. Rowling picks a name for her characters, they usually mean something. Sirius Black references the character's ability to transform into a giant black dog, for instance. But in the case of Tom Marvolo Riddle, she was looking solely for it's ability to be an anagram of "I am Lord Voldemort." It's interesting to note that in the translated versions of the novels, his name is not the same. In French, his name is Tom Elvis Jedusor ("Je suis Voldemort"). In Finnish, Tom Lomen Valedro ("Maa Olen Voldemort"). In Dutch, Marten Asmodom Vilijin ("Mijn naam is Voldemort"). And so on. I can only imagine how difficult this whole anagram business was in kanji.
But let's talk about Riddle. A riddle is a question or a statement that has a double meaning, and it appears in many myths from all over the world. Riddles are probably most associated with the Sphinx. The Sphinx is an Egyptian and Greek creature with the face and breast of a lady, the back legs of a lion, and the wings of an eagle. If you don't answer her riddles correctly, she eats you. Oedipus killed the Sphinx after answering the riddle it posed.
As it turns out, Riddle is a real surname. There is actually a Tom Riddle that is, or was, running for office, which made me giggle. But using it for a first name could be really interesting. Pushing aside the evil wizard association, which I'm guessing will not be people's first thought, it's a cute name for a boy or a girl.
So if you would like a name with a bit of a mysterious edge and a playful side, Riddle could be an option. Just make sure he or she doesn't show a worrisome interest in snakes.