When a Chao evolves, it turns into an adult Chao, it becomes either a Dark, Hero, or Neutral Chao, and it becomes a type of Chao (i.e. swim, run, power ect.). The type that the Chao will become depends on what attribute your Chao is best in, so if you want a run type Chao give it a lot of run type Chaos Drives and Animals. Chao evolve three hours after being hatched. After 5 "Chao Years," Chao will make another cocoon, it will either be pink or gray. Pink means the Chao will reincarnate, and gray means it will die.

This topic is highly confused, even I didn't know what the "2nd Evolution" was until I did some research. Basically, when a Chao evolves into an adult Chao it will be able to go through a second evolution, however it does not go into a cocoon. Still don't get it? Ok then, I will go over it again.... First, the Chao evolves into an adult (Thats its FIRST evolution) then around the age of 3-4 it can go through a second evolution. So, when the Chao is 3-4, start giving it lots of Animals and Chaos Drives. It will start to change again (remember it wont go into a cocoon) it will just start changing on its own (like a baby Chao changes color when it is given Animals).

When you see 'Hero/Run/Swim' the "Hero/" is the alignment (Hero, Dark, Neutral), the "/Run/" is its FIRST evolution (When it evolves into an adult Chao), and the "/Swim" is its SECOND evolution.

When a Chao dies it's because the Chao was unhappy or sick. Chao can get sick but it is not very common its best to take the Chao to the doctor when it is. Chao are probably sick if they start acting weird or start coughing and sneezing. When a Chao makes a gray cocoon theres no way to save the poor thing. What I mean is if you save the game and five minutes later the Chao makes a gray cocoon, starting over wont help its to later no mater how happy you make the Chao.