Offset $2CC contains the sprite IDs of the sprites visible on the screen. Interestingly, there are 6 enemies in the Faxanadu ROM which never actually appear in the game. The IDs of these enemies are 18, 29, 36, 39, 43, 70 (all decimal).
As well, there are two defined NPCs also never actually appear in the game. The first one is the lovely blue lady with ID 53, the other one is the child with ID 54.