"Peril" art of some variety has existed since the golden age of comics in the 1940s and 1950s with Jungle Girl and similar works. (
https://www.deviantart.com/megasonicman ... -796301702 Megasonicmanlover has a screen cap from one of the old pieces). Pop culture art for viewing interest that glorified imperiled heroes and heroines back in the 40s opened up more when the art was easier to mass produce, which is coincidentally around the time that you begin to see the explosion of the pornographic and erotic art industries.
Basically, when it became easier to mass produce art, it became easier to justify the time and energy to mass produce art for erotic stimulation. This is when you start seeing a real proliferation of art in a wide assortment of media and styles. It was not always intended to be 'erotic' per se (The golden age comics rarely were, though there was a lot of male power fantasies tied into many of them.), but one could argue that this began to create an avenue for artists to investigate the media as a personal stimulation.
With the advent of serious digital art and the access to quickly downloadable art and internet and extranet communities in the 1990s, art was disseminated among a wide variety of groups, and you start seeing organized bodies like this. FurryMUCK and TapestriesMUCK along with the mIRC chatboards I knew of in the 90s were basically the earliest places I'm aware of endosomatophiles gathering.
The art as a vessel for an active fascination in getting eaten isn't something that we see strongly prior the golden age. I'm certain there were outliers before that, but it's just not something seen in any heavy form. Basically, until art could be mass produced this easily, it wasn't used in the way we use it for general populace stimulation. They were curios, keepsakes, the property of the rich, in museums and the like. When we began mass producing art, you could get anything you wanted drawn, and with every passing decade, moreso.
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Re: The association of 'Vore and Furries, those who've said that the humans got attracted to a largely Furry pastime are mostly correct. While some of the earliest comic-style art was human in nature, we don't see heavy art until a subset of the Furry community began to demonstrate the interest. They relegated themselves to small sub-rooms in Tapestries (like Omega's Club, or Hell in FurryMuck.), devoted to violent play or specifically to 'vore and as they built up connections, early artists and fans began creating Geocities communities and ultimately websites like YumChat, which was later replaced by Eka's Portal in the mid 2000s.
But as a group of artists explicitly doing mass produced 'vore art expressly for the paraphilic enjoyment of fetishists, we see the first offerings coming out of the Furry community. Since that time, both groups have largely distanced themselves from each other. There's still furries into vore explicitly, but it's not generally a topic to bring up in Furry communities. They don't like to be associated with it. Similarly, a fairly large chunk of people I've met who came here don't like the backwards association with Furries because of the unsurprising reception that they used to get back at Tapestries outside of designated 'safe' areas for the practice. (Not to mention that, until a few years ago, Tapestries used to be VERY elitist towards all non-furs. Not as in 'against the rules' but outright nasty to those who had interests outside of furred communities. It was a large part of why I basically gave up on it. They made an exception for elves, but oh you took so much flack for playing one in most areas.)