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This subject is from the Black Mesa Incident era.This is a safe article.

The Protozoan is an inoffensive creature seen on Xen.


  • The Protozoan appears as a bluish, transparent orb-like entity orbiting above the ground, with a smaller reddish sphere inside, also transparent and turning on itself. It has no AI, cannot be destroyed and does not react to the player's or any NPC's presence.

Behind the scenes

The "protozoan" (Gr. "prôtos", "first" + "zôon", "animal"), also named "protozoon", actually exists. It covers any of a large group of single-celled, usually microscopic, eukaryotic protist organisms commonly living in water, such as amoebas, ciliates, flagellates, and sporozoans.[1] Protozoa can be plants, fungi or animals. Thus the Protozoan can be considered as an extremely enlarged protozoan that does not live underwater.


  • "Protozoa", the model name, is actually the plural form.
  • When viewing its model in a model viewer, it is completely opaque. Its transparency is achieved in-game.


List of appearances


  1. Protozoan on The Free Dictionary