Swiss guards used to serve in the royal household of France, and were considered extremely loyal. During the revolution the palace at Versailles was stormed by revolutionaries, and King Louis xvi and Marie Antoinette managed to escape, but their household guard did not know this, so carried on fighting off the revolutionaries to save a King and Queen who were not there. More than six hundred of the swiss guard were killed in the fighting, which is why the lion has been stabbed in the back and is dying from his wound. Underneath – you can’t make it out in my picture – is written “To the loyalty and bravery of the Swiss”.
The monument was designed by Bertel Thorvaldsen, who apparently was not paid properly by the Swiss for creating the monument, so made the outline resemble a pig if you look very closely – one of the lion’s ears, and also it’s tail is curly – as his way of getting back at them. Although due to my amazing photgraphic skills, that may be hard to tell from the picture.