Gecko ( creature ) Geckos are mutated and enlarged creatures prized for their sleek and durable hides . Before the Great War , they could be found in warm climates throughout the world , ranging from 0 . 39 in ( 1 . 6 cm ) to 27 in ( 60 cm ) in size , with the particularity among other lizards to make chirping sounds in social interactions with other . After the Great War , they ' ve mutated , causing them to grow to giant size . Most of them evolved due to their exposure to the mutated F . E . V . in the air coming from the West Tek Research Facility , while some emerged due to other toxic conditions like massive radiation spills . Characteristics . Geckos are reptilian in appearance and sport a pair of frills behind their head . Their eyes generally have an orange tint , and their body colors differ greatly based on the individual gecko type . All geckos have five fingers , five toes and have kept their pre - War ability to make chirping sounds in social interactions with each other . Gruff breathing , squeaking and cooing can be heard from time to time in gecko - inhabited areas . Like their pre - War cousins , Geckos lack eyelids and tear - ducts and can often be seen using their elongated tongues to lick at their eyes , clearing away dust and small debris . Most regular geckos are peaceful , unthreatening creatures , but if one gecko is attacked , the rest of the pack in the area will quickly converge on the attacker , charging quickly with their mouths open and rapidly attacking with bites and swipes from their clawed hands . Geckos seem to have no strictly hierarchical social structure , with no apparent leader and everyone seemingly being equal in the pack . Some seem to serve as hunters for the pack . Like deathclaw s , they are oviparous , with the eggs typically covered by the father or the mother before the hatching and not laid into a place . Normal geckos and golden geckos have hides that can be turned into all sorts of useful and attractive clothing items . Dresses , jackets and even armor can be constructed from their durable pelts after they ' ve been tanned . Variations . Gecko . The regular gecko is a small - medium sized gecko with indigo skin . Like their cousins the silver geckos , they are mostly peaceful but tend to be rather aggressive in groups . They are very quick on their feet and are fond of using their numbers to rush and overwhelm the opponent . Silver / little gecko . The silver gecko , also called little gecko , is a small sized gecko with silver skin . They are the smallest and least aggressive of all geckos and are not very resistant to damage . They have thus far only been observed in southern Oregon . Golden gecko . The golden gecko is a medium - sized gecko with a rich , golden hide . They are a rarer , but also deadlier breed than the regular or silver gecko . They can be found around irradiated areas in which they lick up toxic waste , causing their particular mutation , making their hides far more " glamorous " than any other kind of gecko , and making their attacks irradiate the opponent . They can be found in southern Oregon and in the Mojave Wasteland . Fire gecko . The fire gecko is a medium - large sized gecko with dark violet skin . They are the second deadliest kind of gecko after the green gecko and , as indicated by their name , can breathe fire due to their constant exposure to sulfur that is now held in their digestive system . Unlike other geckos , they also have large spikes or decorative frills that cover their heads down to their lower back . They are immune to fire and their hides are far too mangy or burned to have any true value . They can be found in northern California and in the Mojave Wasteland . Green gecko . The green gecko is a large gecko with shiny light green skin . They are the most deadly of all geckos , and can spit several slow - moving and far - reaching globs of poisonous saliva similar to . Despite their fragile appearance , they have a high resistance to damage . The cause of their mutation is currently unknown , though some theorize it might be due to ingestion of poisonous plants native to Zion . They can only be found in Zion Canyon . Gojira . Called simply when spawned , Gojira is its editor ID . Its model is identical to that of the , but triple the size , making it roughly equal to a super mutant behemoth in height . It has its own unique embedded fire breath weapon called ' Gojira Flame ' ( baseid 0011324a ) which has a base damage of 400 and an incredible damage per second of 3 , 200 , and a staggering 8 , 000 HP . It can kill anything if one is placed beside it . Not even a X - 42 giant robo - scorpion , or ( the strongest creatures in the game ) stand a chance against Gojira , making it the strongest creature in the game .