(zoology) A protozoan of the family Vorticellidae, common in freshwater ponds.

(dated) A small, globular, locomotive organism (Volvox globator), once thought to be an animal, afterward supposed to be a colony of microscopic algae.

(dated) A flagellate protozoan belonging to Euglena and related genera, having a coloured spot like an eye at one end.

Synonym of wheel animal