Simon was a ship cat who served on the Royal Navy sloop-of-war HMS Amethyst. He was adept at catching and killing rats on the lower decks. Simon rapidly gained a reputation for cheekiness, leaving presents of dead rats in sailors' beds, and sleeping in the captain's cap.
In 1949, during the Yangtze Incident, he received the PDSA's Dickin Medal after surviving injuries from a cannon shell that tore through the captain’s cabin seriously wounding Simon and killing the captain.
The badly wounded cat crawled onto the deck and was rushed to the medical bay, where the ship's surviving medical staff cleaned his burns and removed four pieces of shrapnel, but he was not expected to last the night.
He managed to survive, however, and after a period of recovery, returned to his former duties catching rats. He is still the only cat to have been awarded the Dickin Medal as of 2021.