Changeling

Changelings are a species of shape shifting lifeforms from the Gamma Quadrant.

In there most basic state Changelings resemble a golden translucent liquid and they must revert to this state every sixteen hours to regenerate. Changelings can take on almost any form; liquid, solid, gas and even plasma such as flames. There abilities are limited mainly by there mass, they comfortably take on humanoid forms and can get reassembly larger and take the forms of things a great deal smaller.

The only known population of changelings are the Founders who reside on an unnamed planet in the Gamma Quadrant where they rule over the Dominion as gods. The founders sent out a hundred young changelings into the galaxy at least three ended up in the Alpha Quadrant. The Founders live most of there lives in a collective state in combined liquid form known as the Great Link.

Changelings have proven resistant to Borg assimilation, in 2376 a drone attempted to assimilate a founder on an unnamed planet in the gamma quadrant, the founder compressed herself and the nanoprobes and ejected a ball of nanoprobes with no ill effects to herself. (Star Trek: Deep Space Nine Novel: Mission Gamma Book 4 Lesser Evil)