Vipers are one of the three groups of raiders that originated from Vault 15, the other two being the Jackals and the Khans. The Vipers are mysterious followers of an ancient religion (or so they claim). They usually only come out at night to hunt for food or to conduct raids. They are very ruthless when it comes to combat. They prefer stealth to strength. They usually carry bone knives dipped in Pit Viper venom. This poison, when in the blood stream, paralyzes the victim. Most victims captured in this way are taken back to their hideout.