Fiction:Pseudomorph

"Pseudomorphs" are a species of sapient shapeshifters from the moon Kapanuma, orbiting the gas giant Kematorai, in a red dwarf system in the Cyrannus Galaxy.

Biology
The true form of the Pseudomorphs is unknown, as they can shapeshift into nearly any form, being able to match everything from the external appearance to details of the internal anatomy of any creature they choose. They are not limited taking the shapes of biological organisms, and can disguise themselves as nearly any macroscopic inanimate object. Their only restrictions are that they cannot change their mass or accurately alter their molecular structure, but with their basic psychic powers they can fool all but the most sophisticated sensors into thinking otherwise.

History
Most of the organisms from Kapanuma are fluid, and many of them resemble slime, water, clouds or even lava. Some of them have evolved metamorphic abilities, and these presumably share a common ancestor with the Pseudomorphs. Eventually, the Pseudomorphs developed superior shapeshifting abilities and became an apex predator, and then managed to colonise the rest of their planet over the course of the next few million years.

It does not appear that the Pseudomorphs ever made any efforts to explore space. They most likely felt that it was not necessary for the survival of their species, since they were resistant to any changes in heat or radiation levels that could be caused by space-based catastrophes, and their red dwarf sun would naturally remain stable for the few hundred billion years. Alternatively, the fact that most "ore deposits" on Kapanuma were actually predators disguised as rocks may have precluded the development of advanced technology.

However, Pseudomorphs have been known to exist in several sectors of the distant Plazith Rim Galaxy. It is believed that some Pseudomorphs were taken from their homeworld by explorers, but later escaped their confinement and possibly stole their captors' technology. Then, over the next few millennia, most of the shapeshifters were wiped out, culminating in the destruction of the "Dominion" in the Imperial Civil War. After the war's conclusion, Tokzhalan Imperial ships managed to find the Pseudomorphs' original homeworld and transplated some of the environment to a similar system in the Girdo Galaxy.