Kra- was a Matoran prefix meaning "shadow". When used, it denoted that the object of its reference was associated with shadow and/or the Element of Shadow in particular. The prefix could also be incorporated into names.
Shadow Matoran did not use this prefix, due to not seeing themselves as a "tribe" like other Matoran types.
- The prefix "Kra-" was retroactively derived from "Kraahkan," the name of the Mask of Shadows.
| Regular Elements: Ta- • Ga- • Le- • Po- • Onu- • Ko-|
Moral Elements: Av- • Kra-
Secondary Elements: Fe- • De- • Ba- • Ce- • Vo- • Su- • Fa- • Bo-