Unsinkable Sam (also known as Oskar or Oscar) is the nickname of a ship's cat who purportedly served during World War II with both the Kriegsmarine and the Royal Navy and survived the sinking of three ships. Sam, originally named Oscar, was a ship cat on the German battleship 'Bismarck'. After the ship's sinking, Unsinkable Sam was rescued from the wreckage by the British Navy. Post rescue, Sam is said to have served on the 'HMS Cossack' and the 'HMS Ark Royal', surviving the sinking of both. While the authenticity of this legend is sometimes doubted, the sailors of the British Navy believed it wholeheartedly. The loss of 'Ark Royal' proved the end of Sam's shipborne career. He was transferred first to the offices of the Governor of Gibraltar and then sent back to the United Kingdom, where he saw out the remainder of the war living in a seaman's home in Belfast called the "Home for Sailors". Sam died in 1955. A pastel portrait of Sam (titled Oscar, the Bismarck's Cat) by the artist Georgina Shaw-Baker (1860–1951) is in the possession of the National Maritime Museum in Greenwich.