Answer: protozoa

AnswerCrossword Clue
PROTOZOA

Unicellular critters

PROTOZOA

Microscopic creatures

PROTOZOA

Pond dwellers

PROTOZOA
Little animals.
PROTOZOA
Minute animals
PROTOZOAAmoeba's family
PROTOZOAMicroscopic animals
PROTOZOAMicroscope sights