Child: This is the next stage in a Chao's life and it's very important. You should use this time to get your chao to trust you and to get smart using the Chao Kindergarten, classroom. Your child needs a lot of looking after and caring.
1st Evolution: This is normally referred to as the first proper evolution in the lifespan of your chao. It's impossible not to get this because your chao evolves to this after one Chao age which is two hours. You have to first choose what type you want it to be. Either Dark/Hero or Neutral. To get Dark you have to use a dark character. To get a Hero chao you need to use a hero character. To get a Neutral chao you need to raise it fifty/fifty of each character. Your Chao will also become proficient in one area of his stats.
2nd Evolution: The second evolution is when you get to really mix things up. To get this you need to do some special requirements. I'll do an example to help explain it. My chao is a Power type. The chao's swimming is level 1. Power is 2 and the stamina is 3. I want his second evolution to be Power/Swimming. I first need to multiply his power level by 3 which is 6. Add this to the swimming stat and raise his swimming stat to this level. The multiply his stamina by 3 which is nine and add that on top of the stamina and make his stamina up to that level (12 in this case). You then need to wait 2 chao ages which is 4 hours. Walk out of the garden and walk back in again and your chao will have changed.
3rd Evolution: This is not yet confirmed but the Chao Shrine believes it could be found. They found one for Sonic Adventure 1 so watch this space!!!
Death/Rebirth: This is technically it's final stage. After about 5 chao ages (10 hours) your chao will go into a cocoon. If it's pink your chao will be gone but will be reborn with a brand new egg. If it's grey, sorry mate but it didn't like you and it will be lost forever to the sands of time. If it is reborn it will lose it's stats but it's grades will remain and it will retain some of it's personality. To make find out before hand if it will be reborn whistle at it and if it comes back it will be reborn, but it's not garunteed.