Experimental deathclaw The experimental deathclaw is a in " " . Background . The experimental deathclaws are a group of deathclaw s unique to Secret Vault , a Vault - Tec installation which served as the company ' s ticket to life after the apocalypse . Aside from many scientific projects that were to insure the company ' s power , some research with radioactive materials and FEV took place there . When the Initiate of Brotherhood of Steel visited the Vault , he encountered unique variants of the beast known all over the wastes . The Vault - Tec scientists apparently obtained a sample of the deathclaw bioweapon and tried to improve it , using FEV , radiation and technology . The new species became larger , stronger , gaining extra muscle mass and a type of exoskeleton with many protruding spikes . However , the mutation led them to become blind , leaving the deathclaws to rely on their other senses . The longer they live , the bigger they become , so their mutation and the FEV effect could be very similar to that of Capital Wasteland East Coast - type super mutant . The eggs of these deathclaws are also unique , as they appear more like a pile of flesh nearly the same size as human . Variations . Baby deathclaw . Experimental baby deathclaws are easy to kill . They are dark brown , small and their claws are weak and their skin still has no exoskeleton . Deathclaw . The standard version . This experimental deathclaw looks at least a bit like his normal relatives from the West Coast and Capital Wasteland , but much heavier and stronger . This is the version most common in the Secret Vault , between the Baby and the Elder . Elder deathclaw . The oldest of the experimental deathclaws . They are gray , brutish , and slow . They ' re much stronger and cause more damage than the normal deathclaw . Chameleon deathclaw . Chameleon deathclaw are slightly more evolved than the standard variety . Their adaptive hides help them blend in with their surroundings , rendering them invisible in dark passages . It ' s weaker than the Elder variety but is much harder to locate and faster . Adolescent deathclaw . An extremely unusual prototype variant of an experimental deathclaw . This particular young deathclaw was the subject of an experiment that made him a living colossus . He is the biggest of all deathclaws , possibly all creatures ; larger , even , than a super mutant behemoth . It looks exactly like the standard version but three times bigger and stronger . It ' s presumed that a unique experimental regimen of FEV is to blame , and that the results are intentional . It would seem apparent that the Vault - Tec FEV experimental protocol for this specimen was markedly different from all the others , to result in such a variance of scale and spectrum evident in this multi - story juggernaut . This gigantic deathclaw is known to be a juvenile . FEV also has demonstrated a tendency to cause hosts to " continue " to grow in bulk and size over a lifetime , a trait evident in the elder experimental deathclaws as well . When taken in consideration with the typical lifespans of both unaltered deathclaws and human mutants , these facts begin to paint a clear and sobering picture of the potential size , power , and destruction that this creature contains , and that the Secret Vault science team attempted to exploit . Mother deathclaw . The Secret Vault deathclaw mother is gray , big , and has a highly developed exoskeleton . Her head is protected by a natural crown and she has a lot of spikes coming out from her back . She also has a strange ability to regenerate from radioactive pools found in her den , which is probably is result of modified FEV ' s regenerative features .