The creatures module is a way to represent the creatures and species that inhabit your world. If your world has no use for this module, you can disable it.
Creatures vs Races
A question that comes up is when to use the creatures module vs the races module. This is a fare question, and as always in Kanka, is up to the user.
The main difference between creatures and races, is that characters can be assigned to races, while creatures live on their own.
In that sense, creatures are a worldbuilding element, while races are a game mechanic. Another way is to ask yourself if an entity of a race or creature can become a named character with moviations. If so, making it a race and character might make sense. However, if your players have the speak with animals spell and you name a blue jay creature, simply adding that name as an alias might be enough.
Changing the entity type
If you’ve created many creatures but meant to create races instead, you can easily bulk change their entity type.