The Chao first appeared in Sonic Adventure on the Sega Dreamcast. Since then, these cute little critters have featured in several other Sonic titles, both as part of the series' narrative and in various Chao raising minigames. Players are able to rear their own Chao in a similar way to Pokémon. They can grow stronger, battle other Chao, breed, and they can even evolve.

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There's a lot more complexity to the Chao raising aspects of the Sonic Adventure games than first meets the eye. They have their own special areas in the games known as Chao gardens, and Sonic Adventure 2 fleshes them out even more with the expansive Chao World. Although most players likely won't delve too deeply, the Chao and the world in which they live are full of secrets.

10 There Are Three Different Gardens

Sonic Adventure 2 Chao

Upon first entering Chao World, players will only have access to the first of three Chao gardens. Typically referred to as the normal or neutral garden, this is where the player will be able to raise their first Chao and also access the Chao Stadium. By fulfilling certain criteria, though, it's possible to unlock two more gardens.

If the player raises a Hero Chao, they will unlock the Hero Garden. This can be found upstairs from the Neutral Garden. If the player instead raises a Dark Chao, they will gain access to the Dark Garden, which is found beneath the neutral garden. Interestingly, it's not possible to simply transfer a Hero or Dark Chao to the memory card, meaning that they must be evolved by the player themselves in order to unlock the new gardens.

9 It Uses Sound Effects From The Original Sonic The Hedgehog Game

Sonic Adventure 2 Chao

It might not be entirely obvious to everyone, but there's a nice little Easter Egg connected to Chao World. Upon finishing a stage after finding a Chao Key, players will be transported to the lobby in Chao World. As they are teleporting, a familiar sound effect will play.

Anybody who spent a lot of time playing Sonic the Hedgehog should immediately recognize this sound as the one that's played after completing one of the game's bonus stages. The music for the lobby itself also varies from system to system.

8 It's Possible To Die There

Sonic Adventure 2 Chao

The Chao garden was intended to be a safe place where players could focus on raising their Chao without having to worry about taking damage. Due to an oversight by the programmers, however, it is possible for players to die in the Hero Garden.

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The garden features a wide body of water running through it which was supposed to be too shallow for players to drown in. Due to Tails being a little shorter than the game's other characters, however, there are certain spots where the water is deep enough for him to drown. This was changed in subsequent releases, although not completely remedied.

7 Omochao Was Removed From The Lobby In Modern Releases

Sonic Adventure 2 Chao

Omochao is a small robotic Chao that's been popping up in Sonic titles since the original Sonic Adventure game. In the Dreamcast version of Sonic Adventure 2, Omochao can be found in the Chao Lobby and greets players when they arrive. He then flies around a little before disappearing.

In the later versions of the game, however, there is no sign of Omochao in the lobby. The game instead displays an onscreen message informing players which room they are in. These messages were not present in the Dreamcast release, suggesting that they may have been added to compensate for the lack of Omochao.

6 It's On Its Own Island

Sonic Adventure 2 Chao

By looking at the map screen, it's possible to deduce the approximate location of Chao World. It's positioned on a small island not too far from Central City. How exactly Sonic and the gang make it over to this island is still something of a mystery, though.

Strangely, there are several signposts found in different levels that purport to direct players towards Chao World. These are seemingly just for show, however, as the only way to access Chao World is from the stage select screen or by completing a stage after finding a Chao Key.

5 There Are Hats Hidden In The Gardens

Sonic Adventure 2 Chao

It's possible to buy items for Chao from the Black Market, but there is also a hat hidden within each of the game's Chao gardens. Like the hats purchased in the shop, these can be worn by Chao and are purely cosmetic. In order to find these hidden hats, players will have to enter the gardens while controlling either Knuckles or Rouge and make use of the character's dig ability.

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There are pumpkin hats buried in both the neutral and Hero gardens. In the dark garden, however, players can instead find a skull hat. These hats cannot be purchased from the Black Market, meaning that digging them up is the only way to obtain them. Curiously, their sell-back price is incredibly low when compared to other hats, which doesn't at all reflect their rarity.

4 The Dreamcast Release Allowed Players To Download Rare Chao

Sonic Adventure 2 Chao

The Sega Dreamcast was one of the first consoles with an inbuilt modem, and, as such, many of its titles featured online elements. Although it wasn't possible to play Sonic Adventure 2 online, the game did feature some downloadable content of sorts. Players were able to upload their save files to a webpage and then download different colored Chao depending on how many emblems they had obtained.

Although it's possible to obtain most of these Chao in other versions of the game, they're instead purchased using rings. They're grouped into three sets of three and rotate randomly as the player acquires more emblems. Due to a programming error, however, the game will only select from two of the three sets, meaning that there will always be three colors that can never be obtained. In the PC version, these are yellow, pink, and purple.

3 Each Playable Character Needs To Find A Key To Enter

Sonic Adventure 2 Chao

In order to gain access to Chao World, players will first need to find a Chao Key. Although finding one of these keys will grant access, players will only be able to enter Chao World using the character with which they found the key. Each playable character has their own key hidden somewhere within one of their levels, meaning that there are six different Chao Keys to find, in total.

The Chao Keys are also the source of a glitch that allows players to enter the test level. By picking up the key while the camera's view is obstructed and then completing the level, the game will enter a special state. Players are then able to enter levels using any character. Certain actions will freeze the game, though, as some characters weren't programmed to be able to perform actions that appear outside of their levels.

2 The Dreamcast Release Allows Chao To Be Transferred To A VMU

Chao Adventure on the VMU

The ability to transfer Chao to the Dreamcast's VMU was included in both Sonic Adventure titles on the system. For those unfamiliar with the VMU, it is a memory card with a small screen that plugs into the Dreamcast's controller. Certain titles offered minigames which could be played on the VMU while it was unplugged from the console.

The Chao Adventure minigames work much like a Tamagotchi. Players can increase their Chao's stats and can even breed or battle them by connecting two VMUs together. It's not something that too many players took advantage of, however, as, when combined with the save data for the game itself, it takes up most of the space on the VMU.

1 Two Of The Gardens Are Seemingly Based On Heaven And Hell

Sonic Adventure 2 Chao

Aside from their relative positions to the neutral garden, there are some pretty glaring visual hints that suggest that there's a spiritual influence on the gardens' designs. The Hero garden is up amongst the clouds and features luscious green patches of grass and relaxing bodies of water. While this might not seem too conclusive, the dark garden is a bit less subtle.

It features pools of blood, graves, and skeletons and is just a spooky-looking place, in general. It's very out of keeping with what one might expect to find in a Sonic game, especially given that it's connected to such an innocent aspect of the game. Indeed, Sega seemed to acknowledge this themselves; calling it "a child's worst nightmare" in some of the game's marketing material.

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