Psychlo

The Psychlos are a race of hairy, 9 foot tall, 1,000 pound, sociopathic humanoids. Their homeplanet, Psychlo has an atmosphere very different from that of the Earth, and their "breathe-gas" actually explodes upon contact with even a trace amount of radioactive metals, including uranium.

Background History
The Psychlos discovered evidence of mankind's existence upon accidentally coming across the Pioneer 10. A plaque on the satellite was made of gold-anodized aluminum, a very valuable substance on the universal commodity market. The Psychlos used it to guide them to Earth, where they gassed and killed most of the human population, then invaded to set up a planetwide mining operation, one of thousands of such in their empire. Tiny enclaves of humans linger in wilderness areas, noticed by Psychlos only to "keep them out of the way" of the Psychlo plan of operation. Psychlos are sadistic hunters by nature, and sometimes enjoy a safari after humans. The humans have devolved to pre-technological primitives, and have survived only by living in radiated areas which are slowly driving man to extinction; areas the Psychlos cannot enter safely since their breathe-gas explodes there.

The Psychlo occupation of Earth lasted for a millennium, during which time Earth became a backwater world even for the Psychlos, and assignment to it was considered similar to an assignment to Hell. Around this time, a ruthless (even for Psychlos) and equally greedy Psychlo named Terl was assigned to Earth as security chief, and has his term extended indefinitely for angering the wrong official. Fearful of spending the rest of his years on Earth, he decides to buy his way off the planet while at the same time become ridiculously wealthy. He discovers a large vein of gold in the Rocky Mountains, but cannot go near it himself as it is surrounded by uranium deposits that would make mining by Psychlos impossible. For this task, he captures a human and trains him to do the dirty work for him with a computerized teaching machine. Terl is arrogant enough to call the human "rat brain" and does not notice the human using the machine to learn far more than Terl suspects.

The human uses the machine to train other human miners for Terl, but really trains them for rebellion. This group discovers a way to destroy both the Psychlo on Earth as well as nullify any later threats of retaliation from the planet Psychlo. Semi-annually, the Earth colony teleports personnel, goods, and coffins; in terms of the latter, all dead Psychlos are shipped home for burial upon their homeworld. It is during this routine operation that the human rebellion strikes. They succeed in packing several huge coffins with nuclear dirty bombs and "planet busters" with the hope of destroying the Psychlo homeworld. Upon the teleportation's firing, the humans then take over the Psychlo war planes, tanks, and weaponry to regain control of the Earth.

The dirty nukes and planet busters successfully burnt out Psychlo's atmosphere, killing all of its inhabitants and correctly erasing their threat potential by causing the race to effectively become extinct in the wild.

In film
The appearance of the Psychlos in the film is somewhat altered from the book, although not drastically. In the film, they appear much more human, with only a few being portrayed with exaggerated facial features. They also lack the characteristic mobile "facial bones" found in the Psychlo of the novel. In the film, the Psychlos appear to have elongated "skull bones" from which they grow many dreadlocks. Females lack these dreadlocks and instead appear to have shaven heads where their elongated skulls are evident. However, males of the species seem to lose their hair as they age (much like human males) and their elongated skull-crests are more visible.

Although many aspects of their appearance remains intact, such as the Psychlos' tall stature, talons in place of fingers and their amber eyes.

Additionally, the breath-masks of the film Psychlos are not as cumbersome as in the book. Instead they appear as a small, nose-piercing-like apparatus with two tubes hanging from them.

Psychlo Gun
Psychlo guns are basically a two-in-one weapon, with two barrels - one barrel fires a destructive shot and the other emitting a green pulse that stuns and knocks targets back.