[NSFW] Rule 34 appears valid. Is its corollary true?

TGIF and this time I have a tough one for our NSFW Friday adventure.

“If it exists, there is porn of it. No exceptions.” This memetic Internet “rule” originated from a 2003 webcomic, captioned “Rule #34 There is porn of it. No exceptions.”, which was drawn by Peter Morley-Souter to depict his shock at finding Calvin and Hobbes parody porn out on the Net. Morley-Souter posted his comic on the United Kingdom website Zoom-Out in 2004, and it has been widely reproduced.

According to my rather thorough research, Rule 34 is validated by observable evidence. But how about its corollary? Does the fact there is porn for it mean it must exist somewhere in the real world? What examples of porn can you think of that likely don’t exist at all in the real world, bizarre though the real world may be? If there are no examples of the corollary, can we call that Rule 34-A or should it be Rule 34¬C