Inmates in a prison print shop in Vermont took advantage of an assignment to make decals of the state seal for police cars by subtly altering the image they were handed to reproduce. Now the police have realized there's a pig lurking in their version of the seal, and they're not happy about it.

The seal, which in its original form goes back to the 1770s, shows a cow peacefully grazing under a tree with mountains in the background. But when the prisoners were handed the image to duplicate, one of the cow's spots somehow got transformed into the silhouette of a pig. Before anyone noticed the alternation, the new decals had been placed on as many as thirty cars.

"I apologize to [the police]," Vt. Corrections Commissioner Andy Pallito stated. "We'll have to make sure we do a better job of quality assurance in the future to make sure this doesn't happen again," Pallito expects it will cost about $800 to replace the offending decals.

There appears, however, to be little chance that police will ever identify the inmate who pulled off the clever prank.

This video is from Buzz60, February 3, 2012.