Here's why:

* Eukaryotic: This means the organism has a nucleus and other membrane-bound organelles.

* Unicellular: It is a single-celled organism.

* No cell wall: This distinguishes it from plants, fungi, and most bacteria, which all have cell walls.

Protozoans are a diverse group of single-celled eukaryotic organisms that are often heterotrophic (meaning they get their food by consuming other organisms). They can be found in a wide variety of habitats, including freshwater, saltwater, soil, and even within other organisms.

Some examples of protozoans include amoebas, paramecia, and trypanosomes.

Let me know if you'd like to learn more about protozoans!