I've added beaks to the list already, mouth-pincers would fix the other ideas there. The thing is, a lot of these are just a difference of teeth. "mouth" does not define anything, except for "a hole in the head" and then you add teeth to make "a hole in the head with teeth". When you imagine creatures as the raws make them out to be, it's pretty terrifying. So, a lamprey mouth would simply be a mouth with a few sharp teeth and a strong bite that can latch on easily. I've basically already got circular mouths just by naming them a bit different.
Biome variants - This should hopefully do that pretty well. If you've every played a JRPG (japanese RPG), Tales of Symphonia comes to mind, you'll notice a basic wolf, then a beige desert wolf, then a blue scaled ocean wolf. This should do similar things, except not so explicitly. It makes random critters, so each one is unique, but let's assume that it happened to generate 2 wolves, but in different biomes. The tundra wolf would have thicker fur and fat, while the desert wolf would be smaller and faster. Instead of throwing out creatures, it will attempt to adjust them according to their biome. Most of the time this is invisible, but you should notice that arctic creatures have more "bruising the fat" wounds and badlands creatures have more "chipping the bone" types.
Random creature maker - That's exactly what this is, really, but a bit smaller scale. It makes one creature in its own file, and then you just move that file to the game folder. It will also tell you about it, like "this creature has 4 arms, a tail, and lives in the arctic" but if there's enough desire, I could expand it to make creatures in batches, and populate around a dozen creatures per file, separated by area like the vanilla raws are. This would be very easy, I'd only need to tell the program "repeat the process again" before exporting. Very simple.