Chee

The Chee are a race of ancient, sapient androids created by the Pemalites. They currently live in secret on Earth by use of advanced holographic technology.

Design
The Chee were design to resemble their creators, the Pemalies, which are similar to upright canines. They were built to withstand the rigors of a heavy gravity world giving them enormous strength and speed in Earth's environment. They are equipped with advanced holo-imaging systems allowing them to blend in. In addition they possess an interconnected network called the Chee Net, that allows them to stay in contact with other Chee units in real time. However they have built in program that forbids they from performing or acting upon violence.

History
The Chee are a race of androids, that look like a skeletal dog with interlocking steel and ivory plates, that can walk on their hind legs. They were created hundreds of thousands of years ago by a peaceful and highly advanced race of dog-like aliens called the Pemalites.

The Pemalites were peace-loving pacifists and they programmed the Chee, which means "friend" in the Pemalite language, to never to allow a creature to come to harm. This proved to be their downfall when a race called the Howlers attacked, and the Chee were utterly unable to protect them. The few remaining Pemalites and the Chee fled to Earth, but the Howlers used germ weaponry to finish off the remaining Pemalites. The Chee couldn't save them, so in order to keep part of the Pemalites alive, they harbored their essence into an Earth creature much like them - wolves. It is from that union that the happy-go-lucky domesticated dog was born.

The Chee then blended into human culture by using powerful holograms to make themselves appear to be human, they let their hologram go old and eventually go away, to represent death, and then they take on the illusion of another person. They have been around about the time Pyramids of Giza were erected, and have a secret underground hideout where they take care of stray dogs, which remind them of their long dead creators.

They remained hidden until Marco, with the advanced eyes of an osprey, noticed his friend, Erek King's hologram flicker after he tripped and hit the side of a bus. He then used the eyes of a wolf spider to see through the hologram and find out that Erek is an android.

Andalite-Yeerk War
Several Chee, including Erek, have infiltrated the Yeerk forces on Earth, specifically The Sharing. The Yeerk's technology is not sufficient to distinguish them from humans, allowing them to easily enter undetected. These Chee have taking in Yeerks willingly, keeping the parasitic slugs captive while providing their own Kandrona Rays to the Yeerks inside them and accessing their knowledge. When the time then came to return to the Yeerk pool, they simply project a holographic Yeerk leaving them and "struggle" like an average host.

Despite their considerable physical strength and flawless infiltration, they refuse to do any more than observe and report due to their pacifist programming. Once, the Animorphs and Erek stole a Pemalite computer processor that could allowed Erek to rewrite his programming for violence. He then proceeded to kill all the Controllers around him and save Marco and the others. He then rewrote his programming back to it's original stance, having failed to take into account that, due to the fact that the Chee are incapable of forgetting anything whatsoever, that gruesome battle will be forever burned into Erek's memory, where humans would eventually be able to get past the brutality of what they had done. He gives the crystal to Marco, which gets snatched by dogs and they took it out into the ocean and dropped and got washed away.

After forming an alliance with the Animorphs, the Chee have become a valuable asset as spies, as well as posing as the Animorphs when they're away on a mission. Occasionally, Erek would accompany the Animorphs on a mission where more hands-on disguises or information were required, or Mr. King would lend help with Z-space transmissions.

Towards the end of the war, Jake and the Animorphs forcibly coerced the Chee into assisting with an assault on the Yeerks' Pool ship. The Animorphs and the Chee parted on uneasy terms, but the Animorphs agreed to keep the Chee's secret from the Andalites and humans.