Pick one student to be the wolf and place them in the middle of the gym.
Have all other students line up beside one another at one end of the gym.
Tell all of the students lined up that they must, without telling anyone else, pick whether they will be a dog, a cat or chicken.
When the teacher yells out one of the 3 animals, all of those specific animals (cats for example), must try and run to the other side of the gym without being tagged by the wolf.
The wolf is allowed to go anywhere in the gym, and turns other animals into wolves if he/she tags them.
The last student(s) remaining at the end of the game gets to be the wolf for the following game.
Remind students at the beginning of each round that once they pick their animal they must stay that animal until the end of that particular game.