From Creatures Wikia
The Training Dummy is an agent included in Docking Station. Located in the bottom part of the Workshop, Creatures perceive it as another creature, and can interact with it by pushing it, pulling it or hitting it. The dummy says what was done to it when a creature interacts with it, and you can reward or punish your creatures as you see fit. Activating the dummy yourself always results in a 'push', and encourages creatures to push the dummy. Clicking on the bell on its head changes the dummy from being a 'norn' to being a 'grendel', and then to an 'ettin'. The Dummy Control makes the training dummy mobile.