The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- 0th Biotope (21 members)
- 1st Biotope (10 members)
- 1st Biotope Ecosystem (31 members)
- 3DS (3 members)
- AIR Arc (23 members)
- ANOTHER Arc (45 members)
- Abe Yuutarou's Creation (8 members)
- Acacia's Full Course (8 members)
- Acacia's Kitchen Ecosystem (19 members)
- Admins (5 members)
- Affiliate Headers (123 members)
- Aimaru's Full Course (8 members)
- Alcoholic Ingredients (42 members)
- Alien (3 members)
- Allied Forces (5 members)
- Amphibian Beast (10 members)
- Animal Partners (26 members)
- Animal Tamers (10 members)
- Anime (57 members)
- Anime-only (510 members)
- Anime Images (2 members)
- Anime specials (8 members)
- Annelid Beast (6 members)
- Antagonists (68 members)
- Apparition Beast (2 members)
- Apparitions (12 members)
- Appetite Demons (6 members)
- Appetite Energy Users (18 members)
- Area 1 (5 members)
- Area 1 Ecosystem (4 members)
- Area 2 (6 members)
- Area 2 Ecosystem (11 members)
- Area 3 (7 members)
- Area 3 Ecosystem (4 members)
- Area 4 (6 members)
- Area 4 Ecosystem (5 members)
- Area 5 (5 members)
- Area 5 Ecosystem (7 members)
- Area 6 (23 members)
- Area 6 Ecosystem (25 members)
- Area 7 (17 members)
- Area 7 Ecosystem (41 members)
- Area 8 (29 members)
- Area 8 Ecosystem (43 members)
- Article management templates (9 members)
- Article stubs (45 members)
- Articles in need of images (31 members)
- Articles under construction (7 members)
- Articles with conjectural titles (40 members)
- Artisan (6 members)