The Pfaltzgraff company began making salt glazed pottery in the 1800's. The crocks and jugs were salt glazed with cobalt blue embellishments.
This early pottery was the inspiration for one of the company's most popular stoneware patterns, Folk Art, which was made between 1980 and 1997.
The most common early stoneware decorations were stylized flowers and the mythical Distlefink, which is believed to bring good luck.
I'm pretty sure the Distlefink is the Pennsylvania Dutch version of another mythical favorite, the Chupacabra, which is just creepy.
For more information about the chupacabra, visit the Skeptic's Dictionary at http://www.skepdic.com/chupa.html