The Book of Genesis tells us "There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bore children to them, the same became mighty men which were of old, men of renown." It goes on to suggest that the wickedness of the children of these giants was too great for God to allow, ultimately prompting a great flood that wiped out the giants and their kin (or at least Atlantis and Lemuria). The last remnants of mankind and breeding pairs of essentially every other land animal on earth were, of course, safely ensconced on an ark built by Noah. The famous flood is present in many of the world's myth cycles, with Noah's part played by a variety of other heroes: perhaps the Babylonian Utnapishtim, the Greek Deucalion, or the Hindu Manyu, among others. Of course, the whole thing is probably a giant (ha!) myth. A legend, no matter how commonly held, need not actually be truth.
Or is it?
A Giant Conspiracy
Take a few minutes and watch this video. No seriously. Watch it. It'll take abut 17 minutes out of your day.
Jim Vieira on Giants as Mound-Builders
Intrigued? Here's another one with a little more detail. Be warned, this one is about a hour. But don't worry about it. I'll be here when you get back.
Even More on the Mound Builders
There's not much for me to add to that, except to say that this would make a terrific underpinning for a game. But what kind?
Mounds of Ideas
Assuming for the moment that some few scions of this advanced civilization of double-toothed giants survived to the more recent past, they could easily substitute (or even be the basis for) the Wendigo in our previously-mentioned framework for 19th century Night's Black Agents. The Smithsonian-led coverup Vieira alludes to in the videos above could be evidence of a powerful institution corrupted by the conspiracy. Of course, you could just as easily cast the Smithsonian as the good guys locked in a secret battle with an antedeluvian evil across the forgotten sacred sites of North America. There's certainly significant evidence available -- even above and beyond what Vieira presents -- that Smithson's heirs know a bit more about the history of (semi-) human habitation of North America than they're letting on.
After all, the Smithsonian supposedly sent an expedition to Arizona in 1908 to document an immense cavern showing evidence of a advanced prehistoric civilization with artifacts of a similar style as those found in Egypt and Greece, hinting at a single source for ancient cultures across the world. That the Smithsonian now denies even the existence of the scientists engaged in the expedition is immaterial -- particularly if one assumes that the whole event has been retroactively classified -- perhaps by a secret organization created (and hidden) by the founding fathers themselves? We've already mentioned Atlantis and Lemuria, but the caverns themselves -- and perhaps also the great, hollow mounds of the Ohio and Mississippi River Valleys that Vieira credits to giants -- give us another place to look: the Hollow Earth.
Giants in the earth, indeed.