Chao Evolution

After a while of raising your newly hatched Chao, it will eventually go into a cocoon after a few hours. This is called it’s evolution. Your Chao is evolving from a child to an adult! A Chao is considered to be a child until it evolves.

Dreamcast: One Chao year = around 1 hour

Modern: One Chao year = around 3 hours

Chao can evolve into one of three alignments, and one of five different ability types. This makes for a total of fifteen different possible evolutions! In addition to this, there are three special evolutions, which are separately explained on the Chaos Chao page. The alignment page will detail how to control your Chao’s alignment. This page will explain how to control its ability type, and will present the fifteen different evolutions.

Please keep in mind that a chao will evolve into the alignment and ability type that it favours most at the point it enters it’s cocoon. You can therefore choose how you want it to evolve by choosing what animals or Chaos Drives (and by extension stats) the Chao is given. If you are aiming for a particular type of Chao, you must maintain and keep it how you want it to be until it actually does evolve.

Note!

All Chao in the first Sonic Adventure on the Dreamcast are Neutral alignment. Hero and Dark Chao were not introduced until the next game in the series, Sonic Adventure 2! So there are only five possible evolutions ([)plus the Neutral Chaos Chao) in this game.

Ability Types

A Chao doesn’t just evolve into a Hero, Dark, or Neutral alignment: it also evolves into one of five different ability types. Depending on what animals and/or Chaos Drives you have given your Chao, it will evolve in a certain way. There are four main groups of animals and Chaos Drives and this is what determines the Chao’s evolution path; it will evolve into one of five different ability types. These ability types are Swim, Fly, Run, Power, and Normal (where no stat is favoured over the others).

It is very commonly believed that a Chao evolves into the Swim, Fly, Run, or Power types if the corresponding stat is the highest, and that the Normal type is based on HP/Stamina or a balance between the other four stats. All of this is completely false! Evolution is more complicated than that, and actually is not based on stat values at all. Instead, it is based on a Chao’s recent interaction with animals or Chaos Drives.

A Chao evolves into a ‘Normal’ type if it has recently interacted with animals/drives in a balanced way. This includes when it has been given nothing at all! Here are two examples to help explain this:

  1. You give your Chao 100 Run animals, then 100 Power animals, then 100 Fly animals, and then 100 Swim animals. You have given it an equal amount of every type, but only over a long period. Most recently, you have only given it a large amount of Swim animals. The Chao will evolve into the Swim type.

  2. You give your Chao 5 Run animals, then 5 Power animals, then 5 Fly animals, and then 5 Swim animals. You repeat this process 20 times, so that it has had a total of 100 of each kind. Because the Chao most recently interacted with a balance of all types, it will evolve into the Normal type.

The above explanation was just a summary of how it works. For more in-depth information on this, see the wiki page.

Chao Evolution Images

Neutral Evolutions

Before EvolutionAfter EvolutionAlignment / Ability TypeDescription
Child Normal ChaoAdult Neutral Normal ChaoNeutral/NormalThis looks just like a normal newborn Chao, except it has green highlights instead of yellow ones. Its body is also a different shade of blue, and it has a patch on its stomach. It also has a sandy-brown ball floating above its head.
Child Swim ChaoAdult Neutral Swim ChaoNeutral/SwimThis Chao has a green and yellow body, with dark green highlights on its forehead. It also has a green ball floating above its head.
Child Fly ChaoAdult Neutral Fly ChaoNeutral/FlyThe NiGHTS Chao. This Chao has a pinkish purple body, with sandy-brown highlights on its stomach and feet. It has large, beautiful green-blue wings, and two long, curving spikes with violet highlights emerging from the back sides of its head like a jester hat. It also has a tangerine-coloured ball floating above its head. This Chao resembles the Sega character called NiGHTS, from NiGHTS into Dreams.
Child Run ChaoAdult Neutral Run ChaoNeutral/RunThis Chao has a green body, with dark green highlights on its head. It has big feet and three large spikes on the back of its head. It also has a light green ball floating above its head. The shape of this Chao resembles Sonic the Hedgehog. If you continue to give it Animals and Chaos Drives from the green group (Running), it will change colour to dark blue and resemble Sonic even more as it grows older.
Child Power ChaoAdult Neutral Power ChaoNeutral/PowerThis Chao has an orange body, with red highlights on its stomach and yellow highlights on its head, hands, and feet. It has three spikes emerging upwards from its head. It also has a sandy-brown ball floating above its head.

Hero Evolutions

Before EvolutionAfter EvolutionAlignment / Ability TypeDescription
Child Normal ChaoAdult Hero Normal ChaoHero/NormalLike all Hero Chao, this Chao has a white body and inverted eyes. This particular evolution has two angled buds sticking out from the top of its head. The Chao has blue markings on his hands, feet, and head buds, and yellow highlights on its stomach. It also has a turquoise halo floating above its head.
Child Swim ChaoAdult Hero Swim ChaoHero/SwimThis Chao has green markings on its body, with two long, flat leaf-shaped protrusions on the top of its head. It also has a yellow halo floating above its head.
Child Fly ChaoAdult Hero Fly ChaoHero/FlyThis Chao has purple markings on its body, with two short, curving leaf-shaped protrusions on the top of its head. It also has a purple halo floating above its head.
Child Run ChaoAdult Hero Run ChaoHero/RunThis Chao has blue and yellow markings on its hands, and blue and purple markings on its stomach. It has a small, straight spike sticking up from the top of its head. It also has a yellow halo floating above its head.
Child Power ChaoAdult Hero Power ChaoHero/PowerThis Chao has red markings on its head, chest, hands, and feet. It has three buds on the top of its head, each sticking out at different angles. It also has a purple halo floating above its head.

Dark Evolutions

Before EvolutionAfter EvolutionAlignment / Ability TypeDescription
Child Normal ChaoAdult Dark Normal ChaoDark/NormalThis Chao has a very dark red body, with some red markings on its chest, hands, and feet. It has a jagged tip at the back of its head. It also has a purple spiked ball floating above its head.
Child Swim ChaoAdult Dark Swim ChaoDark/SwimThis Chao has a black and aqua body. A small spike sticks out from the back of its head and angles up sharply. It also has a turquoise spiked ball floating above its head.
Child Fly ChaoAdult Dark Fly ChaoDark/FlyThe Reala Chao. This Chao has a dark purple body, with lighter purple markings on its head, hands, and feet, and darker purple markings on its face and stomach. It has two sharply angled spikes emerging from the back sides of its head like a jester hat. It also has a blue spiked ball floating above its head. This Chao resembles the Sega character called Reala, from NiGHTS into Dreams.
Child Run ChaoAdult Dark Run ChaoDark/RunThis Chao has a dark body, with bright green markings on its head, chest, arms, and feet. It has three large, sharply angled spikes on the back of its head. It also has a dark blue spiked ball floating above its head. The shape of this Chao resembles Shadow the Hedgehog. If you continue to give it Animals and Chaos Drives from the green group (Running), it’s highlights will change colour to red and resemble Shadow even more as it grows older.
Child Power ChaoAdult Dark Power ChaoDark/PowerThis Chao has a dark body, with orange and red markings. It has a cone-shaped head with a wavy, striped top, and striped hands. It also has a yellow spiked ball floating above its head.