Beast, Bird or Fish
Players sit in a circle, with one player in the centre.
The player in the centre holds a soft ball or sponge which she throws as unexpectedly as possible at one of the circle players while simultaneously calling either "beast" or "bird" or "fish". Then she immediately counts to ten.
The person holding the ball must yell out a type of animal in the category named, before the count is completed. no words can be duplicated. If the player cannot name an animal, she must change places with the player in the middle.
To make it easier for younger kids, you could play this game after an activity about animals, so they have more ideas. Also, decide beforehand what type of things fit in the categories -- you can include insects as beasts, and aquatic creatures (shellfish, etc) as fish to give you a wider range from which to choose.