That’s a dismissive expression people use when they believe that something is impossible. I’ll admit that I haven’t seen a pig fly (yet), but did you know that pigs are now saving human lives?
Known as xenotransplantation, earlier this month, surgeons at University of Maryland Medical Center (UMMC) transplanted a pig heart into a 57 year old man who was otherwise out of transplant options. He lived – and continues to live. Check out this video!

More than 20 years in the making, pig organs may soon become one (of hopefully many) viable new options for human organ transplants.
BTW, surgeons also transplanted a pig heart into a baboon as well – and it worked!