Go to the Mystic Ruins. Go to the water fall located in the middle of the Adventure Field. Push the stone that is jutting out of the wall to the right of the water fall. A silver egg will fall from behind the waterfall and float to shore. When it hatches, a silver Chao will be born.

Go to the Station Square area. Then, go to the area when you fought Chaos for the first time. Look to the side of the City Hall entrance to find an egg shaped rock. Take the rock to the building to the left from City Hall. Walk to the window to see a golden Chao egg. However, if you try to take it the front door will lock. Replace the egg with the rock and the door will unlock, allowing you to leave with the egg. When the egg hatches, a golden Chao will be born.

Go to the egg carrier. Then, go the jail area where Amy was kept. In the cell next to where she was held is a black and blue egg. Step on the switch to open the door. Take the egg to the garden. When it hatches, a dark grey and dark blue Chao will be born.

Collect at least 100 emblems to get access to a special section called the Black Market on the Dreamcast Network site. A Special Chao can be downloaded from this area.

To get all five of the Chaos Emeralds that you can get with the Chao, you need to log on to the Dreamcast Network site and go to the Chao Daycare Section. Download one of the Chaos that are 999 in all four categories. Return to your Chao Garden and race him in a Chao Race. He will easily defeat all the other Chao. Repeat this on all five races to get the five possible Chaos Emeralds.

Sonic

Light Speed Shoes: Sewer in Station Square.
Crystal Ring: Elevator on second floor of hotel.
Ancient Light: On rock near bridge to Angel Island.

Tails

Rhythm Badge: Follow Tikal to past (it is on a pyramid).
Jet Anklet: In the sewer behind Twinkle Park.

Knuckles

Fighting Glove: In the cave near Angel Island.
Shovel Claw: On a cliff behind Big The Cat's house.

Amy

Warrior Feather: Defeat Hedgehog Hammer for the first time.
Long Hammer: Defeat First Place score again.

Big The Cat

Life Belt: In the lake in the cave leading to Angel Island.
Power Rod: In Forest under Big's bed.
Lure 1: In Sewer Behind Twinkle Park.
Lure 2: In a cave in the Forest.
Lure 3: In the Icecap level.
Lure 4: In a prison cell on the Egg Carrier.

E-102 Gamma

Jet Booster: In the Ammunition Room of the Egg Carrier.
Gun Upgrade: In the room opposite the Ammunition Room.

Sonic: 30 emblems to collect in Sonic's Action Stages.
Tails: 15 emblems to collect in Tail's Action Stages.
Knuckles: 15 emblems to collect in Knuckles Action Stages.
Amy: 9 emblems to collect in Amy's Action Stages.
Big the Cat: 12 emblems to collect in Big's Action Stages.
E-102 Gamma: 15 emblems to collect in E-102's Action Stages.
Adventure Field: 12 emblems to find in Adventure Field.
Mini-Games: 10 emblems to collect in Mini-Games.
Chao Races: 5 emblems to collect in Chao Races.
Complete the game with all six characters to get 6 emblems.
This brings the total number of emblems that are collectible in the game to 130.

Heart: Happy
-- over eyes: Happy
Swirl: Angry
XX over eyes: Angry
Flailing Arms: Angry
Question Mark: Confused
Exclamation Mark: Surprised
Half Closed eyes: Tired
Waving Arms: Wants Attention