Creature Isle is an expansion of Black & White, it has new story, which happens on one huge island (orginal B&W had multiple lands in story mode). There lives a community of godless creatures, The Brotherhood. They learn together and help each other out. Your creature can join them, and for that, this island has a lot of Trials (mini-games), which need to be completed. There are no other gods, so you can explore and play without any danger of being attacked. After becoming a Brotherhood member, your creature will get a golden ring, which shows his achievement. In future this ring can be seen by other players in multiplayer games.
Some new features of CI:
1) Now your creature can get a little helper, Tyke. Basically, he is a pet of your pet. And trust me, this annoying little bastard will make you wish him dead. You can use Tyke in multiplayer (optional), but why would you want that?
2) Your creature can learn how to make buildings (not only finishing already started building, but also starting new ones, without any scaffolds). When doing so, creature will waste all of the wood that is connected to that building site, even if there is much more than needed. So, be careful how much wood you put there.
CI is based on version 1.10. That is why it does not have everything that versions 1.20 and 1.30 have (mostly multiplayer features and support for a special controller), but in other ways it is more advanced, has more bugs fixes, new bugs and so on.
Creature Isle was released by Lionhead Studios in 2001.