A colony creature or colony species is a lifeform composed of multiple component organisms that functioned together.
Coral, a marine organism found on Earth, was a type of colonial lifeform. (VOY: "Future's End")
The "giant tribbles" that occupied the USS Enterprise for a short period of time were eventually found to be colonies of tribbles that clung together, but which could be separated by neoethylene. (TAS: "More Tribbles, More Troubles")
Pandronians, such as Ari bn Bem and Shari yn Yem, were colony creatures whose constituent parts were capable of independent function. (TAS: "Bem"; LD: "I, Excretus")
In 2364, the microbrain became a colony of single cells which organized like a computer, and was more powerful after an energy surge in its reproductive cycle, (TNG: "Home Soil")
The Tuscadian pyrosome was a colony species consisting of thousands of interconnected zooids. (DIS: "All Is Possible")