Euglena's a genus of unicellular protists, of the class Euglenoidea of the phylum Euglenophyta. They're single-celled organisms. Currently, over 1000 species of Euglena have been described. Marin et al. (2003) revised the genus to include several species without chloroplasts, formerly classified as Astasia and Khawkinea. Euglena sometimes can be considered to have both plant and animal features. A euglena's a protist that can eat food like animals do (partly heterotrophic) and can photosynthesi… (More on Euglena)