( Decipher RPG module: Aliens) Changelings can take on almost any form liquid, solid, gas and even plasma such as flames. But, by doing so, they were able to create a sophisticated facsimile of flesh and matter allowing them to even take on clothing.
They were unable to mimic an object through a simple glance and were required to see enough of the item or person they wished to copy in order to perfectly take its form. This allowed a Changeling to adopt any shape and texture that they desired so long as they studied the shape long enough. ( DS9 episode: ' The Search') This gelatinous substance which was held in a morphogenic matrix that activated into different shapes and textures through the use of a special enzyme. ( TLE novel: Night of the Wolves) In their most basic state Changelings resemble a golden translucent liquid. They were noted for their capacity to alter their form to levels that were beyond that of similar shape changing species such as the Wraith, Vendorian and Chameloid races.