|Habitat||Shadow leech hive|
|Tools and Abilities||Sucking the moral light out of beings|
- —Narration, BIONICLE Legends 9: Shadows in the Sky
A Shadow Leech was a mutated Kraata created by Mutran, Tridax and Chirox that had the ability to suck elemental and moral light out of a being, similar to one of the functions of the Kanohi Avsa. For example, a Matoran whose light has been sucked out of would then become a Shadow Matoran, gaining the element of Shadow and losing their original element. The only known cure for infection by a shadow leech was the sonic scream of a klakk. All Shadow leeches were killed by the Energy Storm.
- Gavla (former Av-Matoran, later reversed by a Klakk)
- Kirop (former Av-Matoran, later reversed by a Klakk)
- Takanuva (gaining the element of Shadow, later reversed by a Klakk)
- Vican (former Le-Matoran, the first known victim to be cured by a Klakk)
- Vultraz (former Ta-Matoran)
- The features of the Shadow Leech pieces in the 2008 Makuta sets were not similar to how they were described in the BIONICLE books; the leeches were described as being at least two feet in length.
- Radiak was not a victim of a Shadow Leech; his light was actually sucked out by Makuta Vamprah's Kanohi Avsa.