Childkiller

Child Killer

You have killed children, the youth of the wasteland. This is considered to be a really bad thing. You evil, evil person.

The Childkiller perk (though, it is hardly a good thing) is obtained from killing any child, hostile or not. Having this status will not affect your character greatly, but will make you unable to successfully talk to some children, such as the one near the brahmin pens in the Hub that gives a quest.