Mastigophora, also known as flagellates, are a group of protozoa characterized by the presence of one or more flagella, which they use for locomotion. They can be found in various environments, including freshwater, marine, and soil habitats, and some are parasitic, causing diseases in humans and animals. Notable examples include Giardia lamblia, which causes giardiasis, and Trypanosoma species, responsible for sleeping sickness and Chagas disease. Mastigophora are classified within the broader kingdom Protista.