Timebomb

Timebomb is a badly injured man inside Red's Clinic at Big Town. If your Medicine skill is 40, you can heal Timebomb. If your speech skill is high enough you can try to milk him for some caps and if you are successful he will give you all he has, 5 caps. Also you may acquire a "lucky 8 ball" (granting a +1 Luck attribute bonus as long as you carry it) after doing the quest Big Trouble in Big Town. However, if you blow Timebomb's head off before healing him and before doing the quest then once you have finished the quest and healed him he will walk around town with a disfigured skull, jaw, eyes, and brain floating behind his actual head position. Not to mention his neck is still ripped in pieces.

You also have the option of putting him out of his misery. Doing so gives bad karma, and a message calling you a callous bastard.