Kingdom Protista
In the Protista kingdom, organisms are unicellular and multicellular, some have a cell wall, and are Eukaryotic. The organisms can be both Autotrophic or Heterotrophic. Protista can be found in everyday environments, they're similar to animals, plants, and fungi.
Examples
Volvox globator (which is a green alga), Paramecium caudatum (a single-celled protist usually found in aquatic environments), and Physarum polycephalum (a slime mold).
Interesting Facts
1) Some constantly change shape
2) Some feed on bacteria
2) Some feed on bacteria