The Animal Kingdom: Protista consists of single-celled organisms, such as a protozoans and simple alga.
Here are links to a few microorganisms to get you started.
Amoeba are one-celled organisms that live in wet environments including ponds, wetlands, wet soil, and even human bodies. They have a movable shape and can extend pseudopods to reach for and engulf prey. They prey on smaller organisms, such as bacteria.
Euglena are one-celled protozoans with a whip-like flagellum that they use to propel themselves through their aquatic environment. Some euglena species have chlorophyll, so can produce their own food through photosynthesis.
Paramecium are one-celled organisms that are covered in hair-like cilia that beat to propel them in a spirals through their aquatic environments. They feed on bacteria and other small protozoans.
