The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Undergrounds (BZPRPG) (1 member)
- Unknown; Appears to be a Toa, but really isn't. (Bionicle Kingdoms IV) (1 member)
- Unknown (BZPRPG) (3 members)
- Unknown (BZPRPG I) (1 member)
- Unknown (BZPRPG III) (1 member)
- Unknown Characters (BZPRPG III) (2 members)
- Unknown Elementals (BZPRPG) (1 member)
- Unknown Species (3 members)
- Unknown Species (BZPRPG) (4 members)
- Unknown Species (Bara Magna (Series)) (3 members)
- Up To Date (BZPRPG III Arc 3) (12 members)
- Ussalry (16 members)
- Valkyr (1 member)
- Valkyr (BZPRPG) (1 member)
- Vault Loot (2 members)
- Vector Art (4 members)
- Venom Elementals (A City Divided) (1 member)
- Visic (7 members)
- Vo-Toa (22 members)
- Vortixx (19 members)