Unfortunately, I'm not an expert in this area. It seems that all the files of that game are located in a file with the .BIG extension. I once extracted the soundtracks from it. The models are very similar to the creature models in Heroes, and the animations are too. But whether they will be suitable for this game, I honestly can't say.
If possible, try to take a screenshot of the contents of the .big file in that converter (extractor) that you used to extract the sound ;)
