Get animals and pick them up and give them to your chao and watch it change but if you give it anything else it might change.
(NOTE:This cheat might bring some of your chao stats down.)
First Buy an expensive item from the black market in the chao kindergarten, e.g. an apple, a box, a worn out pan. Next go and put the item in any garden and exit chao world so it saves. Then go back into chao world in the garden you put the item in take it to the black market and sell and then exit the black market and get clear of everything and hold X B Start together so it resets and go back in chao world and your rings will go up for how much you sold the item for and the item will still be in the garden.
Press A and you will cheer your Chao on.He will use his Stamina Level to go faster for about 2 seconds.WARNING: If your Chao uses all its Stamina, it wil go way slower than the other Chao.