Special Encounter: A Lone Surviving Dog

You'll arrive at the scene of massive carnage, though a single dog has apparently lived through the devastation. If you fail a Luck check, the dog will begin following you around as the Pariah Dog. As soon as it's part of your party, you'll gain the Jinxed perk and your Luck will be reduced to 1.

The only way to be rid of the dog is to kill it, unfortunately. It has a ridiculous number of hit points (750), so this won't be an easy task. If you don't want to use conventional means, you can use trapped locations to inflict damage to the dog or you can even use the extraction device within the Sierra Army Depot Bio Research Lab. It will actually take two extractions to get rid of the dog and you'll end up with a serious karma reduction and two Human Brains out of the process.