The "Sons" of Makuta who are suits of armor animated by sluglike beings called Kraata. 

There are 42 different species of Rahkshi, but only 7 have been seen so far:

[[Turahk_(bionicle)]], Rahkshi of Fear
[[Guurahk_(bionicle)]], Rahkshi of Disintegration 
[[Lerahk_(bionicle)]], Rahkshi of Poison 
[[Panrahk_(bionicle)]], Rahkshi of Fragmentation 
[[Vorahk_(bionicle)]], Rahkshi of Hunger
[[Kurahk_(bionicle)]], Rahkshi of Anger
[[Rahkshi of Heat Vision|rahkshi_of_heat_vision]]
rahkshi (bionicle)