Start off in cat pose, extend your right arm out in front like a big claw ready to take a swipe at your pray and then take the left leg out the back ready to pounce on your pray this is tiger pose.
Your class might even like to add a big scary tiger noise to this pose this will help you to keep the kids in the pose a little longer as the children try to hold the balance.

Always with tiger pose it is the opposite arm to leg. Lots of kids will try to stretch out the arm and the leg of the same side and will find it really hard to balance. Working with the opposite arm and leg not only makes it easier to balance but helps the children to work the left and the right brain co ordination especially if you change sides a number of times.