In year 4, I used this idea to assess children's learning in our habitats topic.

The children were asked to design and label their own animal thinking about how it is adapted to live in its environment, diet, camouflage etc. It was a great way to assess children's knowledge and understanding of the associated vocabulary.

They loved doing such an open ended task and using their imaginations. The children could also make their animal from clay and present it to the class.

The 'Build Your Wild Self' site might also be a useful tool for this activity.