First, pick a character. I suggest you use Amy, since her jump doesn't hurt chao, but it doesn't matter. Go to the Egg Carrier. Go up near the entrance to the Sky Deck. On the ground you should see a little floating 'elevator'. Jump on it and go below deck. You could also use the monorail if it is running at the time you do this. Once you get below deck, hop down to where the maintenance robots are working. You should see three door. Hop on the button farthest to the right do go in the right door. You should see where Amy plays Hedgehog Hammer. Go past that and enter the 'dungeon'. In the first cell you should see a black speckled egg. That's your chao! Open the cell and take it back to the Egg Carrier Chao Garden.