This game is strictly for fun, but is also a good focusing tool and helps a group to let go of inhibitions.
Organize the group into a circle sitting on the floor. The goal of this game is to keep a straight-face, and not laugh. Someone starts by going into the center of the circle to do their best imitation of a cat, without using any words. The individual advances on one person and tries to make him or her laugh. If the cat is successful, the laugher becomes the cat. If not, the cat chooses another member of the group to amuse. If the cat has a difficult time amusing anyone, congratulate the group on their focus, and choose another cat.
As you understand, the variations are possible, choosing another animal as a model. Showing a dancing elephant might be much fun as well. For the advanced exercises, there is no need to limit the task with pets, animals, or even traditionally moving objects. What about presenting the moving bridge, or jumping cupboard?