Krana In the LEGO BIONICLE universe , each Bohrok contains a parasitic Krana which acts as its brain and gives the Bohrok its power . Enhanced Bohrok called Bohrok - Kal have similarly enhanced Krana called Krana - Kal . General Information . The Krana are intelligent organisms that are telepathically guided by the Bahrag , twin queens of the Bohrok swarms . With this guidance , they control and direct the inanimate Bohrok shells to do the Bahrag ' s bidding . Krana were originally created by the Great Beings , by exposing the leftovers from the process of creating Matoran to energized protodermis . However , some of this material became not Krana , but a reptilian race called the Zyglak ( see " Zyglak " , below ) In the present time , the Bahrag immerse some unknown matter into energized protodermis instead of Matoran leftovers , without the risk of creating Zyglak . The Krana , while the Bohrok ' s strength , is also its weakness : even the strongest Bohrok , without its Krana , becomes little more than an empty shell . That shell can then be programmed or trained to repair the damage it inflicted . One of the main functions of the Bohrok Va scouts is to replace a Bohrok ' s missing Krana . If a Krana feels threatened , it can eject from its Bohrok host ; this leaves the host powerless , but if the Krana attaches onto another being ' s face , it takes control of the other being ' s mind and assimilates it into the swarm . The Toa Mata collected 48 Krana ( eight types of Krana times six types of Bohrok ) , and placed them into special slots in the middle of the Bohrok nest . This unlocked the hiding places of six sets of Exo - Toa armor and the lair of the two dreadful Bahrag twins . When the Bahrag were defeated , the Bohrok shut down and the Matoran collected all their Krana , threw the Krana into pits and sealed them away . Krana - Kal . Krana - Kal are specialized Krana , mutated to have stronger abilities . Like regular Krana are literally the brains of the Bohrok , the Krana - Kal are the driving force of the Bohrok - Kal . The Krana - Kal are unlike the other Krana in the way that they can act independently , without depending on the Bahrag ; and they are able to communicate with other beings via telepathy . Krana - Kal also contain a unique property which allows them to turn a silver and gold color and generate an impenetrable shield around their hosts when at the final stages of their mission . Krana Types . The eight types of Krana each have their own name and rank in the swarm . Krana - Kal , though having identical shapes and similar names to ordinary Krana , have slightly different ranks and powers . Krana Colours . Each Bohrok breed uses Krana of different colours . There are actually two colours per breed : a Krana is its " active " colour when controlling a Bohrok or some other being , and changes to its " inactive " colour at all other times . This inactive colour is sometimes thought of as a Bohrok Va Krana , as their job is to carry around spare , inactive Krana . In addition , Krana - Kal have their own metallic colours . Collectibility . Each Bohrok , Bohrok Va , and Bohrok - Kal set came with one random Krana of the appropriate colour . Further Krana could be collected from Krana packs produced by LEGO , so that all 144 variations could be found . Rare silver Krana Xa - Kal were also made ; 5 , 000 of white metal and 72 of actual sterling silver ; included at random in North American and United Kingdom Bohrok - Kal sets . If you have the Toa Mata or Toa Nuva toys , the Krana masks can be attached to the unmasked faces . Zyglak . An accident of the Krana ' s original creation by the Great Beings , the Zyglak are a savage reptilian race . Shunned by their creators and universally despised , the Zyglak retreated to dark , desolate areas , all the while harboring bitter hatred against the Matoran , their Great Spirit , and all loyal to them . Zyglak are amphibious , and live in desolate areas where nobody else will go . The Toa Inika encountered some in the stone cord that connects Voya Nui and Mahri Nui , and some of the Barraki found a group in the ruins of the original Pit . Toa Lesovikk also discovered that Karzahni rounded up Zyglak to help him attack Mahri Nui . Zyglak carry knives , spears , and other weapons with blades that destroy whatever they hit . It is unknown if or how they are affected by the Pit ' s mutagenic waters ( the mutagen is thin in the deepest part of the Pit were the Zyglak live ) . They are also known to carry a dangerous organic - protodermis destroying disease which is spread to other beings through touch .