Here is a web program that scans one or many zip files and repackages them into the correct folders. So all agent files go to the agent folder, c16 to images folder, cos files to the correct bootstrap folders, etc. Just pick the game in the top left corner drag drop the files, and away you go.
https://github.com/vipero07/creatures-zipper
The actual tool itself:
https://vipero07.github.io/creatures-zipper/