I honestly just assumed it was some temporary Internet meme joke thing akin to Bowsette. I didn't realise there were people out there who took things that far that they fetishised these things or actually dressed as or had sex in....furry fox costumes lol. Genuinely I just don't even fucking know what the fuck is anything any more lol.
You never seen a porno where people are dressed as famous super heroes or characters from popular movies or what not? Its not exactly unique to the furry community by any means. Try going to any big name scifi/anime convention.