Max and the Surprise

Once upon a time, there was a little dog named Max. Max loved to play fetch in the park with his owner. Every time his owner threw the ball, Max would run quickly to catch it and bring it back. One sunny day, Max noticed that his owner had a special surprise hidden in his backpack. Max could only imagine what it could be. He wagged his tail excitedly and kept looking at the backpack, hoping to find out what the surprise was.

What do you think might happen next?