Final answer:
In "The Time Machine," the creatures that lived underground were the Morlocks, a metaphor for the exploited Victorian working class.
Step-by-step explanation:
In the novel "The Time Machine" by H.G. Wells, the creatures that lived underground were known as the Morlocks. These beings are one of the two post-human species the Time Traveler encounters in the distant future. Unlike their counterparts, the Eloi, who lived above ground, the Morlocks are depicted as more sinister and are presented as a metaphor for the working class of Victorian society. The book explores themes of class struggle, where the Morlocks, analogous to the working class, are forced to live and work in the darkness, out of sight of the leisurely upper-class Eloi. This depiction reflects the societal fears and tensions of the era, suggesting that beneath the veneer of Victorian civility and progress, there lurked potential monstrosity and a propensity for exploitation, similar to themes in other classic Gothic novels like "Dr. Jekyll and Mr. Hyde" and "Dracula" that explore the darkness lurking within the elite.