Here is all the toys that I know of. If I missed any, please tell me!

The shovel
Uses: A chao can use this to plant seeds found in Chao adventure 2. (see chao adventure 2 section)

Watering can
Uses: A chao can use this to water his seed/tree in the chao garden.

Rattle
Uses: Chao enjoy

Toy car
Uses: Chao enjoy

Balls
Uses: Your chao might see the ball rolling around in the garden, and when it does it will chase it. Which ball goes where? See FAQ page

Pogo stick
Uses: Chao enjoy

Boom box
Uses: Chao enjoy

T.V.
Uses: Chao enjoy

Jack-in-the-box (also known as box of doom)
Uses: I can't figure one out.

These are all that I can think of, so if I missed any please email me from the below link.