Have the boxes identify the object falling in by its tag. you have three tags, bearToy, dragonToy, elephantToy.
Have an fsm that lets you click on the toy object and when the player clicks on the object it sends an event to the next state which changes the sprite and the tag from bear sprite and tag to dragon sprite and tag. Etc...
You can also set it so that you have an Int variable on the object. 1 - Bear, 2 - Dragon, 3 - elephant. Every time you click it changes to the next int and you have another fsm that compares the ints and if 1,2 or 3 it changes the sprite to the corresponding int. Then you can have the box grab the int from the toy and check to see if it is the right int.
That should do it!