The Hidden Influence of Empire of the Petal Throne

Though Empire of the Petal Throne is a game with which I am now intimately familiar, I didn't really know all that much about it until the early 1990s, when the growth of the Internet made it possible for me to make contact with RPG players outside my local circle. Prior to that, I only knew two things about EPT: it was very expensive and that its setting of Tékumel was weird and inaccessible. Because I never ran into anyone who was actively playing the game in those days, I assumed that it was due to a combination of these factors, particularly the latter. 

There's almost certainly some truth to my youthful surmise. Empire of the Petal Throne and its setting of Tékumel have never had much mass appeal, even in a hobby filled with creative, imaginative people with a high tolerance for eccentricity. However, that doesn't mean EPT didn't leave its mark on the development of the hobby – quite the contrary, in fact. I was reminded of this the other day when I stumbled upon the following image:

This is an illustration of a monster from Tom Moldvay's Lords of Creation RPG. Called a "scavenger wheel," it appears in the game's The Book of Foes and is described as having "a 4 foot wide spherical body covered with tentacles between two 6 foot tall wheel-like appendages." Compare that illustration to this one, which appeared in issue #4 of Dragon (December 1976): The creature in the back is the Vriyágga (seemingly illustrated by Dave Sutherland, though the style doesn't quite look right to me). The article it accompanies describes it as having "a huge pair of wheel-like appendages [that] revolve around central axes like the treads of a tank" and "from the lower part of the parody of the face depend four (or more in larger specimens) great tentacles covered with powerful suckers." The Vriyágga is such a singularly bizarre thing that I think it highly unlikely that Moldvay wasn't inspired by it.
However, that's not the only instance where a monster from EPT inspired one in another game. There are (at least!) two others that come immediately to mind and, in these cases, we have confirmation of this fact from none other than Gary Gygax. The first is the Ngóro, which is described as "huge (30 feet in length) creatures lie flat upon the floor of a chamber and appear much like the rough stone flooring of the Underworld, although they may feel a little springy to walk upon." The second is the Biridlú, "cape-like, black, flying creatures which cling to ceilings and drop down upon the unwary. They then suffocate their victim, gibbering and shrieking in their powerfully muscled folds." These are very clearly the original sources of the trapper and lurker above respectively.
Though not a popular success, I increasingly get the impression that Empire of the Petal Throne was much better appreciated by many of the roleplayers who would one day become game designers themselves. As a result, its influence was much wider than many might imagine, given its seemingly small footprint in the hobby at large. After all, we have EPT to thank for the introduction of double damage critical hits to roleplaying and that's got to be one of the most well-known and pervasive house rules of all time (and eventually an official feature of D&D's own Third Edition, despite Gygax's earlier denunciation of the concept). 
I now find myself wondering where else EPT might have left its mark on the hobby without our realizing it.