The following is from Greg Farshtey, BIONICLE™ comic author and unofficial keeper of the legend. It has been minimally edited for style and clarity.

There are six different breeds of KRAATA that we know about. That does not mean that is all there ever have been or could be. They are:

• KRAATA-Vo (included with VORAHK)
• KRAATA-Xi (included with PANRAHK)
• KRAATA-Ye (included with LERAHK)
• KRAATA-Ul (included with GUURAHK)
• KRAATA-Cu (included with KURAHK)
• KRAATA-Za (included with TURAHK)

KRAATA are a part of the substance of MAKUTA. They are sentient, but they are not deep thinkers. They act on instinct.

Each KRAATA goes through six stages of development. The stages do not have names at this time. Greg calls them KRAATA Stage 1, KRAATA Stage 2, etc. As it develops, the KRAATA makes its RAHKSHI stronger, faster, and more powerful.

If you look at the pictures of the KRAATA on the back of the RAHKSHI instruction book,

a Stage 1 KRAATA is at the bottom (the weakest), a Stage 6 KRAATA is at the top (the most powerful).

The touch of a KRAATA can infect a KANOHI mask. KRAATA have been on Mata Nui almost as long as the MATORAN have, and the TURAGA have been capturing and imprisoning them in stasis for years. (The canisters they come in are like stasis tubes.) KRAATA cannot communicate with TOA, although they probably can with each other.

There is a special seventh stage of KRAATA which very few of them ever reach — the SHADOW KRAATA, which is more intelligent and capable of infecting masks at a distance.

It takes two KRAATA to make a RAHKSHI. One KRAATA, exposed to protodermis, evolves in the tube into the RAHKSHI armor. The armor remains dormant until another KRAATA enters it and basically becomes the driver. Note: The KRAATA that animates the armor MUST be the same kind of KRAATA as created the armor. You cannot start up a PANRAHK with a TURAHK KRAATA and expect it to work properly.

A RAHKSHI’s power is part of the RAHKSHI, but the staffs are required to focus and control it. If a KRAATA is removed from a RAHKSHI, the RAHKSHI returns to dormancy.