Answer: protozoan

AnswerCrossword Clue
PROTOZOANAmoeba, for one
PROTOZOANMinute life form.
PROTOZOANSingle-celled organism
protozoanany member of the Protozoa also PROTOZOON
protozoanone-celled organism that obtains nourishment by ingesting food rather than by photosynthesis