Chaos.... ( pronounced Chows )
Are normal living creatures that appear in Sonic adventure games.
They also make cameo appearances in other games such as Smash 3DS and Wii U. These things will be for Sonic Adventure 2 battle.
Let's start with the basics
There are three ways of hatching Chao eggs, with each way having different effects on your Chao.
Shaking or rocking the egg is the most common way of hatching an egg. Pick up the egg using the B button, and while still holding the button down, move the analogue stick to shake it. After about 5-10 seconds of shaking the egg, place it back down on the ground. The egg will start to bobble, and then your Chao will hatch from it.
You can also throw the egg to break it open. To do this, pick up the egg by pressing the B button, and then throw it by pressing the B button again while moving. It may take multiple throws to break the egg open.
Your Chao will not look very pleased at first if you use this method, but there do not seem to be any negative effects from doing this. All that will happen is that the Chao will start with an angry/upset expression above its head; however, this expression will only last a few moments, and the Chao seems perfectly happy afterwards.
Many people choose to hatch their eggs in this way because it is far quicker than the other two methods. Some guides, manuals, and magazines have said that this method produces a more active, lively Chao, but this is unconfirmed.
Your Chao egg will hatch naturally after a while, even with no interaction from you. Simply leave the egg alone and it will hatch by itself. Hatching a Chao this way has been said to produce a normal, perhaps timid Chao; however, this is unconfirmed and should be considered idle speculation.
Your first Chao
When you first start, you will have two Chao eggs in the Chao Garden. As you later unlock other Chao Gardens, you will find that each one of those has a single Chao egg. These eggs contain regular, normal coloured Chao, which are light blue with yellow highlights. They will change in shape and color as they grow.
This stat determines how well your Chao can swim, or if it can swim at all. It is therefore very important for races that contain a lot of water, as a low Swim stat will cause you to lose your position to the better swimmers. An extremely low Swim stat will mean your Chao can't even swim in the Chao Gardens, and will instead thrash about in the water!
You can increase the Swim stat by giving your Chao animals and Chaos Drives from the yellow group. A Chao first learns to swim when its Swim stat reaches 100 points.
This stat determines how well your Chao can fly, or if it can fly at all. It can be very useful in races where your Chao has to jump down from a height, as it can use that opportunity to pull ahead if its Fly stat is high enough.
You can increase the Fly stat by giving your Chao animals and Chaos Drives from the purple group.
This stat determines how quickly your Chao can walk or run, or if it can walk at all. It is probably the single most important stat for races; nearly all the races have a huge emphasis on running, and your Chao will have a significant advantage if it has a high Run stat. An extremely low Run stat will mean your Chao can only crawl very slowly across the ground.
You can increase the Run stat by giving your Chao animals and Chaos Drives from the green group. A Chao first learns to walk when its Run stat reaches 20 points, and its walking speed increases at 100 points.
This stat determines how strong your Chao is. It is mostly needed for climbing cliffs in the races, where a higher Power stat will allow your Chao to climb up faster. Some races also have trees which require strength from your Chao in order to shake a nut down before proceeding.
You can increase the Power stat by giving your Chao animals and Chaos Drives from the red group.
This stat determines the physical constitution of your Chao. It is one of the most important stats for races, as it determines the size of your Chao's energy bar. Your Chao's energy will decrease throughout the race, and if it runs out, your Chao's speed will drop immensely. You can also cheer for your Chao during the race using the trigger buttons, which will give it a temporary speed boost in exchange for a chunk of energy. What this all means is that a high Stamina stat allows your Chao to keep its speed level and get additional speed boosts!
You can increase the Stamina stat by giving your Chao any kind of fruit, either ones that grow on trees in the gardens or ones that you purchase from the Black Market. The Mushroom from the Black Market will raise Stamina significantly, but costs 300 rings.
There are also Luck and intelligence, but i'll explain those later. Information was from the chao island.