An organism made of more than one cell working together is called a multicellular organism.

Here's why:

* Cells: The basic unit of life.

* Multicellular: Made up of many cells.

* Working together: The cells have specialized functions and cooperate to carry out the organism's life processes.

Examples of multicellular organisms include:

* Animals (humans, dogs, insects, etc.)

* Plants (trees, flowers, ferns, etc.)

* Fungi (mushrooms, molds, yeasts)

* Algae