I tried that once.
The game wouldn't have my shit and completely failed to break, despite my urgings.
This was what the first creature raw looked like, approximately. It loaded. It showed up in the loading screen, and the tiles went apeshit since I didn't define any for the creatures. But the game itself, somehow, decided to ignore it.
creature_creature
[OBJECT:CREATURE]
[CREATURE:CREATURE]
[NAME:creature:creature:creature]
[CREATURE:CREATURE]
[NAME:creature:creature:creature]
[CREATURE:CREATURE]
[NAME:creature:creature:creature]
[CREATURE:CREATURE]
[NAME:creature:creature:creature]
[CREATURE:CREATURE]
[NAME:creature:creature:creature]
[CREATURE:CREATURE]
[NAME:creature:creature:creature]
[CREATURE:CREATURE]
[NAME:creature:creature:creature]
[CREATURE:CREATURE]
[NAME:creature:creature:creature]
[CREATURE:CREATURE]
[NAME:creature:creature:creature]
[CREATURE:CREATURE]
[NAME:creature:creature:creature]
[CREATURE:CREATURE]
[NAME:creature:creature:creature]
[CREATURE:CREATURE:CREATURE:CREATURE:CREATURE:CREATURE:CREATURE:CREATURE]
this didn't even show symptoms of duped raws, i was so disappointed
from that day forward, i decided: i won't try to break the game again, it's too tame
I know for a fact that I want things in a mod, though. DF already has things, unfortunately. Demons, angels, forgotten beasts, titans. All are very thingy. But they have descriptions that are quite descriptive. It's better not. Better not. I don't want to know what the things I'd make would look like and neither do you. ASCII has the brilliant ability to do that.