But how did the pig get there?

It was on this date in 1977 that Pink Floyd's concept album "Animals" hit store shelves. It was allegedly inspired by George Orwell's book, Animal Farm.

The theme behind the record was people as animals. Businessmen were compared to dogs, pigs were the upper echelon who manipulated the middle class and sheep were considered to be people who mindlessly follow the herd.

The cover art for the album features a pig floating between the smokestacks at the Battersea Power Station. The pig was a helium filled balloon named Algie. It was supposed to be tethered into place for the photo shoot and a trained marksman was hired to shoot it down should it break free. The weather was less than ideal for the day they were to photograph the pig and the shooting was delayed. Someone forgot to book the marksman for the second attempt and the pig ended up floating away. It landed in a farm field and the band decided to attempt the photo shoot for a third time, but earlier photographs of the power station were considered to be better, so the entire photo shoot was scrapped and the image of the pig between the smoke stacks is actually superimposed.