Long ago, I read that comic Tales of the Morphing Period. Great enough concept, not really realistic. I mean, no offense to the comic, which I did enjoy, but I tend to think a bit darker. SO I took the idea, and went a bit further, what if the strain that mutated humans into anthros, wasnt the orginal purpose of the virus. What if, in the meat industries attempt to cut corners for more profit, fed the cattle a drug that would produce more meat? Bigger cows, sheep and pigs. And in the process, it was rushed into the marketplace without testing. As a result, the virus mutated with the animal meat, and in most cases, mutated whomever wound up eating it and made them bigger too. What you see is the end result. I had drawn a story about this, and now I think I will dig it up and put it on here.
Also, to the casual browsers, I put a couple of other pig TF sketches in the scraps section...