I'm a fan of Rule 34.
When I say that I mean that I often find rule 34 porn that I find very sexy (Pokemon, Puzzle and Dragons, Monster Hunter all come to mind), but also that seeing rule 34 of things, even when those things are not relevant to my personal interests, nonetheless makes me happy.
So to that end, I thought it might be fun to see what things rule 34 has failed to apply to. That is, things of which, to the best of anyone's ability to determine, porn does not exist.
Not talking "combinations" here, for the record, but single subjects.
So, post some things you've looked for porn of, and failed to find. Feel free also to prove someone else wrong, if you've seen porn of that thing, or if you want to make it, I guess. Maybe I'll maintain a list of the things which haven't been disproved if anyone but me enjoys this topic.
I'll start out with two:
It might be more fun to stick to characters you think have good enough designs that someone might want to draw them for reasons other than filling a rule 34 quota, but hey, I leave that to your judgment.
*Edit: Because there has been a lot of misunderstanding of this point, this thread is for things for which absolutely no pornography exists. Zero. If the character you're thinking of has any r34 at all, it's not a proper failure of the rule.
Updated by GavinDittmar