Cyberdog Cyberdogs , also called cyberhounds , are dog s with at least one mechanical part and one organic part . Their physical and mental abilities have been modified robotically and cybernetically , creating a kind of canine - robot hybrids . Cyberdogs are rare and creating one is extremely difficult , requiring both a high degree of technical sophistication and generalized breeding and training programs . As such , they have only been produced by technologically advanced organizations such as the pre - War US government , the Enclave and the research team of Big MT . Cyberdogs were generally used before the Great War in specialized units serving the military and also by some larger police departments . Characteristics . Cybernetic canines models . Cyberdogs have the appearance of cybernetic canines ( although two exceptions exist ) with a yellow sclera ( only the " cyberhound Mk III police model " have a normal , white sclera ) . Cyberdogs of this type are also called " K - 9 units . " Despite being highly modified with electronic parts , they are not affected by pulse weapons . Their modifications include : Some standard cyberdog models are : Unique models include K - 9 and Gabe . K - 9 was created by the Dr . Schreber in the Enclave outpost of Navarro and based on the " Cyberhound Mk II personal security model . " He includes all the standard modifications above with : Gabe was created by the Dr . Borous in the Big Mountain Research and Development Center and based on the " Cyberhound Mk III police model . " He includes all the standard modifications above ( excluding the speech capability ) with : Weapon models . A peculiar model ( and an outstanding exception to the standard cybernetic canine ' s appearance ) is the K9000 cyberdog gun , created to act as a personal operated , handheld weapon system . Instead of the standard cyberdog units , which are canine in general anatomy , the K9000 cyberdog gun is more akin to a heavy weapon . It is a living dog ' s brain that has been provided with a machine gun frame utilizing the . 357 Magnum ammunition . Its " canine " features include two metallic " ears " mounted on top of the weapon that move like a real dog ' s and a sniffer mounted on the jar containing the brain , which allow the gun to sense its surroundings . It can be enhanced with a resla roil increasing its damage by 2 and a mentat chow to increase its rate of fire by 4 . Another exception is the upgraded version of the K9000 cyberdog gun , the unique FIDO . Unlike the K9000 cyberdog gun , FIDO uses . 44 Magnum rounds instead of . 357 Magnum rounds , resulting in higher damage , but it also has a slightly higher spread . It has a special red brain instead of the standard green one of the K9000 cyberdog gun and the decal is changed from a golden retriever to a bulldog . It can ' t be enhanced with the same modifications as available for the K9000 cyberdog gun . Other features of the K9000 cyberdog gun are included in the FIDO . Variations . Cyberhound Mk II personal security model . Robodog is a cyberdog , more specifically " cyberhound Mk II personal security model . " Dr . Henry brought it from the Enclave Oil Rig and settled down in the NCR . Cyberhound Mk III law enforcement officer support model . Rex is initially under the ownership of The King and needs a new brain due to neural degeneration . During the Nothin ' But a Hound Dog quest , he can be turned into a and optionally cured of his condition . Cyberhound Mk III military model . The military cyberdog has a sonic bark used as a weapon , and has a chance to knock down the player character with its melee attack . They also appear to have the ability to self heal / repair themselves . Cyberhound Mk III police model . A slightly weaker variety of the military cyberdog . They can be distinguished from military cyberdogs by their unique black and white paint , as well as the red and blue reflective patches on their backs . K9000 cyberdog gun . A rather unusual cyberdog in that all of the original canine biological parts have been discarded , except for the brain , which is now housed in the body of a heavy weapon style firearm . It fires . 357 Magnum ammunition . " Canine " features include two metallic " ears " mounted on top of the weapon that move like a real dog ' s and a sniffer mounted on the jar , allowing the gun to sense its surroundings and causing it to growl when pointed at an enemy , even when the enemy is out of the vicinity of the weapon . It can be enhanced with a resla roil increasing its damage by 2 and a mentat chow to increase its rate of fire by 4 . FIDO . FIDO is a unique and more advanced version of the K9000 cyberdog gun , using instead of . 357 Magnum round s and having slightly higher spread . The brain case and the scope are red instead of green for the K9000 cyberdog gun , and the decal is changed from a golden retriever to a bulldog . Other features of the K9000 cyberdog gun are included in FIDO . Appearances . Cyberdogs appear in " Fallout 2 " , " " and the " Fallout : New Vegas " add - on " Old World Blues " .