Dark Chao

The Dark Chao is a creature that appear in the Sonic X comic series published by Archie Comics. It is an artificially-created Chao breed cultivated by Dr. Eggman for one of his schemes which could turn into destructive monsters when exposed to a radio signal.

Anatomy
In their default state, the Dark Chao look like regular Chao. When switching to their Dark Chao state, their skin turns black, their yellow tippings become red, and their eyes become white with blue sclera. They also grow sharp teeth, their round tails turn into red-tipped devil tails, their wings become bat-like, they gain a red crescent symbol on their chests and their floating dot becomes spiky.

Characteristics and culture
In their default state, the Dark Chao initially exhibited the loveable and pleasant mannerisms of regular Chao. Over time however, they grew increasingly more moody, showcasing confusion, restlessness and aggressive behavior. Being created from Cheese's DNA, they referer to him as their parent and displayed awareness of Dr. Eggman's plans for them.

In their Dark Chao state, the Dark Chao become a destructive force of nature. Extremely aggressive, wild and ravenous, they only show interest in causing as much destruction and chaos as possible and will attack anyone in sight, all while showing a mischievous, if not malicious glee over the mayhem they would cause.

Like regular Chao, Dark Chao can only speak one word which comprises an entire language. Instead of saying "Chao" however, they say "Choa." Also, to those that understand Chao speech, it is like the Dark Chao speak a different language and have really bad accents.

Powers and abilities
In swarms, the Dark Chao are a force of absolute desolation; Tikal herself implied that, if left unchecked, the Dark Chao could have destroyed the entire Earth.

When exposed to a certain radio signal, the Dark Chao transform into their evil alteregos. In this form, Dark Chao have incredible strength for their size: a single one could swing a whole couch around and three of them could uproot a fire hydrant. They have likewise a powerful bite that lets them easily chew through even metal. All Dark Chao are also capable of flight.

Like regular Chao, Dark Chao have the ability to hear certain radio signals.

Archie Comics
Using a clipping of Cheese's wing, the Dark Chao were created by Dr. Eggman and nurtured in his lair's Chao Garden to take over Station Square. Launching an advertisement campaign labeling the Dark Chao as pets, Eggman managed to sell thousands of them to the citizens of Station Square in the span of a month. Then, to force Station Square to surrender to him, Eggman sent out a radio signal that made the Dark Chao switch to their evil alteregos and go on a city-wide rampage. Despite Sonic and his allies coming to the rescue, the Dark Chao overwhelmed them until Tikal and Chaos arrived with an army of Chao to fight the Dark Chao. In the meantime, Chuck Thorndyke created a short-range device that could counteract Eggman's radio signal and convert the Dark Chao into regular peaceful Chao. With his speed, Sonic used the device on every Dark Chao in Station Square and Tikal took them with her into the Master Emerald.

Despite their failure, Eggman would keep some Dark Chao and hold them within his tower base.

Trivia

 * The Dark Chao are based on the Chao with the same name which first appeared in Sonic Adventure 2.