CHANGELINGS

Changelings are a race of shapechangers from the Gamma Quadrant. They can appear as virtually anything they wish. They must return to their natural form, a gel-like liquid, once every 16 hours. Without this rest, they will find it increasingly harder to maintain the morphed shape. They only need to stay in this "natural" form for one hour. Their mimicry abilities give them an uncanny ability to duplicate virtually anyone (or anything) they have ever seen. They can change form, shape, size, and color at will, and can do so in just a few seconds.

Combine the above with their Body of Plasm, and they are a very effective double agent, among other things. You would have to know the victim of a Changeling switch -very- well in order to detect their impersonation at all. The races of the Alpha Quadrant have recently discovered that pieces removed from a Changeling's body will revert to their natural gel-like form. Blood tests are now standard protocol throughout the Federation and Klingon Empire to weed out Changeling infiltrators.

Members of this race can stretch their bodies even while maintaining a regular form. They do not need to eat or drink, at least not in any known manner, and their need of sleep is quite different from normal humanoids. They do not even need to breathe, but their bodies cannot survive in the vacuum of space without a suit of some type.

Changelings have a fanatical hatred of "solids" and have attempted to infiltrate militaries and governments of several Alpha Quadrant races, including the Federation. It is not known how far this process has gone.