The Bismarck marked one of the most formidable battleships ever constructed, the equivalent of an "ocean-bound castle," according to History. It was also the first full-scale German-built battleship since World War I. Because of the ship's state-of-the-art design, Nazi leaders claimed it was unsinkable. Of course, history tells us that claims like these prove incredibly foolhardy, which Oscar would find out firsthand.

Accompanying the formidable Bismarck was the heavy cruiser Prinz Eugen, the largest warship of its day. Their top-secret mission, codenamed Operation Rheinubung, involved bringing the British naval fleet to its knees. The Bismarck's first engagement proved impressive, according to History. On May 24, 1941, the battleship Prince of Wales and the battlecruiser Hood ran across the Bismarck off the coast of Iceland. Engaging the enemy, the Bismarck didn't disappoint, eventually sinking the British navy's crown ship, the Hood, in a spectacular explosion. All but three of the Hood's more than 1,400 crew members perished.

While the Bismarck proved sound, it had a fuel leak, forcing it to head towards the coastline of occupied France for repairs. But the cat was out of the bag. (Pun intended.) By May 26, the Royal Air Force walloped the Bismarck, disabling the ship. While we can only guess what Oscar was up to during these tense days — his feline follies likely included plenty of food and nap time. But his life changed forever on May 27, when three British naval battleships rendered the Bismarck a sitting duck. Shockingly, the crew chose to scuttle the vessel, sending it (along with more than 2,000 sailors) to a watery grave (via the Scotsman).