A groundhog is a bit like a wombat, only cuter. And not a marsupial
They are renowned for their ability to predict the weather.
A groundhog is ritually tortured in a small, otherwise unremarkable, Pennsylvania town every February 2nd. Just like in the movie.
A gentleman in a mourning coat and a top hat drags it out of it's pretend burrow and brandishes it at the crowd, while another, similarly attired gentleman reads a proclamation that tells if there will be an additional six weeks of winter from that day forth.
The Official Punxsutawney Phil Site
(that's pronounced PUNKS-uh-taw-nee, by the way. Pennsylvania and Australia may have to fight over strangest place names, although you've got a good chance with places like Woolamaloo and Woomera. We on the other hand have Wissahickon, Conshohocken, and Susquehanna).