Browsing a toy display at the discount outlet, T. J. Max, while my wife looked at clothes, I found Hasbro's G.I. Joe figures. Joe has been through many mutations since I owned the original Vietnam era version of him in the '60's. Nowadays "G. I. Joe" is the code name for an elite operations team fighting Cobra, a ruthless terrorist organization.
I was drawn to the Cobra Mole Pod, because it looked so much like old illustrations of the "iron mole" from Edgar Rice Burroughs's first Pellucidar novel, At the Earth's Core.
Sean Long has an amusing demo of the Cobra Mole Pod:
Sean Long likens the Terra-Viper action figure to Darth Vader. I am at a disadvantage, not having seen the film G.I. Joe: The Rise of Cobra (2009), but I have to wonder why the Rise of Cobra's bad guys have such an odd, fantasy-rpg/Star Wars/Ninja provenance. Oh G. I. Joe, how thou art fallen!
I didn't much care for Burroughs's most famous creation, Tarzan, but I loved his Martian Barsoom novels. The "hollow earth" Pellucidar books I mostly remember for their gorgeous Ace paperback covers by Roy Krenkle. The "iron mole" has been rendered by several artists:
From the 1976 film with Peter Cushing:
Moles are technically named Tunnel Boring Machines, (TBM's), but in real life these are unmanned. I'd rather call the Cobra and Pellucidar machines Subterrenes.
The oddest result I got searching for this was a man who built a "giant steampunk drill" in his yard for Halloween this year.
Stories featuring TBM's are a small subset of Hollow Earth fiction.