The randomly-generated creatures don't have RAW files like the new underground creatures do. They may have files associated with them in the individual save folders, but I haven't checked.
There's a few new creatures in the other files, though. Buzzards have been added to the large_temperate file, vultures to the large_tropical file, and yetis to creature_standard. Several creature_subterranean (NOT _next) creatures have been changed. Snakemen, lizardmen, and frogmen are out, and replaced with serpent-men, reptile-men, and amphibian-men. There's also now cave-fish-men. Olm-men, bat-men, and cave swallow-men are still present.
Ant-men are still present, but have undergone radical changes. They now have queens, workers, drones, and soldiers.
I can't find any mention of rat-men in the files anymore. I may just have missed them, however.
Tigermen seem to have had some major changes to their file. They're still wild 'animals', but they now have can_speak and can_learn. The various subterranean animal-men have these tags as well. This means you can come across animal-men with things like "Fighter" or "Spearanimalperson".
I've probably missed a few creatures. This was just a quick search through the files, nothing comprehensive and detailed. Additionally, just from looking through legends, it appears that some creature names are present without being otherwise present in the game. You can have demons that look like twisted anteaters, for example, despite there being no anteaters in the game.