If it exists, there’s online porn of it — that’s what people call “Rule 34” of the Internet. But it turns out there’s need for an addendum: If it doesn’t exist, there could well be porn of it, too. Enter Bigfoot erotica.

This phrase sounds like a punchline, yet it’s the whole story in a Virginia congressional race. Democratic candidate Leslie Cockburn has slapped on her Republican opponent the unprecedented label “devotee of Bigfoot erotica.” The entire ordeal may smell like an attention-seeking stunt, but as long as Bigfoot is on the brain, we might as well think seriously about how he, and the rest of us, got here.

Once upon a time, Republican Denver Riggleman shared from his Instagram account a crudely (and crassly!) drawn image of Bigfoot with a decidedly large “CENSORED” box covering his genitalia — along with another image with Riggleman’s face superimposed on Sasquatch’s face, ostensibly to promote the release of a “magnificent tome” titled “The Mating Habits of Bigfoot and Why Women Want Him.”

The only evidence of this opus is a since-deleted author page for Riggleman on Facebook. But he is the co-author of the self-published “Bigfoot Exterminators, Inc.: The Partially Cautionary, Mostly True Tale of Monster Hunt 2006.” That book is not erotic.

What theoretically is erotic is the trove of reading material that many describe as “monster porn,” and others refer to as “cryptozoological erotica” or “erotic horror.” These stories feature fantastical figures and their trysts with (usually female) homo sapiens. Sometimes, the damsels aren’t in distress at all: They want this as much as the monster. Other times, it’s the monster who distresses them: The creature captures the heroine and then ravishes her. In the end, though, the monster possesses sexual prowess no mere mortal can claim. And the lady almost always leaves satisfied.

Bigfoot has competition, from cthulhus to centaurs to cyclopses. But he, on his own, commands an impressive share of the monsterotica market, in tales such as “Boffing Bigfoot” and its less tamely titled counterparts. And these stories position the Sasquatch as the embodiment of physical power and what it can bring to bear in the bedroom: Bigfoot represents the ultimate alpha male.

Cockburn’s attack on Riggleman implies that an interest in Bigfoot erotica is disqualifying. “This is not what we need on Capitol Hill,” she intones. Those whose predilections lie outside the mainstream might call this kink-shaming. If women, or men, consider the concept of a mythological liaison attractive, that’s none of our beeswax.

But if we take Riggleman at his word, he’s not really interested in sexy sasquatches, at least not in the manner of a true Bigfoot erotica devotee. This was all a riff, Riggleman says, with his “buddies” from the military. They found the concept compelling enough to engage with it on an elaborate scale, but only from the distance derision provides.

That makes sense. In a culture of masculinity, the alpha-maleness central to monster erotica has a certain allure. On the one hand, the stories are threatening. Women wouldn’t need the Bigfoots of the world, after all, if men could do the job themselves. On the other hand, it’s tantalizing for men to think women do desire someone who exercises complete physical control, and that maybe, just maybe, they could pull it off, too. That aspiration certainly comes through in the photoshop of the Rigglemanized sasquatch sketch, massive member and all.

No wonder, then, that Riggleman leaped to explain at length that Bigfoot does not turn him on in the slightest. Imagine the emasculation. On the contrary, Riggleman insisted, what he’s interested in is the community of “Bigfoot believers” and the arguments they have — did the Sasquatch descend from the great ape, or from homo erectus, “which, you know, it’s a man, baby,” and how do you hunt him?

Riggleman says he’s a skeptic, but his self-published book on the topic features him and his friends embarking on Bigfoot takedown expeditions themselves. The pages are plastered with camouflage and guns and words like “cojones.” It’s decidedly more macho, after all, to focus on man’s ability to destroy the alpha than the alpha’s ability to take man’s wives as their paramours.

It’s unlikely Cockburn had any of this in mind when she sent out her tweet lambasting Riggleman, and it’s unlikely he has delved into the implications of his curtailed affair with monster erotica either. But the social valences of a subject most have laughed away remind us that every piece of Internet culture has its roots in the world beyond the Web, and that every joke we make online says something about who we are when we log off. Call that Rule 35.