Protists

Kingdom Protista is one of the six kingdoms of life. Protista in general are a very unorganized group because of the variety of characteristics in the organisms in the kingdom. For example, some are multicellular while others are unicellular. Also, some are heterotrophs while others are autotrophs. Some are plants with cell walls while others are animals without cell walls.
Protozoans are referred to protists with animal like traits such as the ability to move across water. True protozoans are eukaryotes and usually single-celled heterotrophs. They have special organs that make them move like flagella or cilia. Some example would be malaria, which is a protozoan that is harmful to humans, and amoeba, which can move by changing the shape of its body.

Malaria

Amoeba