Meow is a font for cats. Every fourth letter a cat types, turns into the word "meow."https://github.com/jpt/meow
This debuted at the Stupid Shit That No One Needs and Terrible Ideas Hackathon in San Francsico, of course. It works for 52 letters, uppercase and lowercase. We ran into some interesting OpenType limitations when dealing with 7.3 million programmatically generated ligatures
When fed "sub [a-z] [a-z] [a-z] [a-z] by m_e_o_w.liga" makeotf would crash, we tried it a different way that I don't remember but there was a limit, maybe on lookups, I think 8,512? We tried some other stuff and found makeotf is hard coded to timeout after 100,000 attempts while recycling -- https://github.com/adobe-type-tools/afdko/blob/master/FDK/Tools/Programs/makeotf/makeotf_lib/source/hotconv/feat.c#1686
Eventually we split the alphabet into many different classes and also got down to a reasonable 2,400 lookups. The repetition bug, I'm not sure how to fix, but then maybe that makes it even more useless, which was a goal from the start.