I think that you have to be careful about throwing out labels to describe Lost in Space, though. Monsters made very numerous appearances throughout the series, but they are not all of a type. There are a number of distinct purposes for the appearance of one, and I would like to list a few. As a third category, there are monsters that are integral to the plot of an episode or to a subplot within the episode. Quano’s beast in the cave in “The Challenge” is an example of this. Other examples are Uncle Angus in “The Astral Traveller” and the bush creature in “The Raft.”