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).

Unfortunately, Oscar wouldn’t have long to get comfortable on the HMS Cossack, according to Uboat. Five months after the sinking of the Bismarck, on October 24, 1941, a German U-boat shot two torpedoes at a destroyer, missing the ship. But one of the torpedoes launched into the HMS Cossack. The explosion blew the Cossack to bits, destroying “most of the forward section, killing the commander.”

Over 150 crew members died in the explosion, and 60 survived, including 29 wounded sailors. Although a skeleton crew would later re-enter the ship, attempting to salvage it with the help of the tugboat HMS Thames, it sunk on October 27 because of extreme weather. Fortunately, the volunteer crew on board managed to escape before the ship slipped beneath the waves. Again, Oscar survived, although he may have surrendered the second of his nine lives during this naval disaster.

Where did Oscar end up this time? After the second sinking, he began life as a member of the aircraft carrier HMS Ark Royal (via All That’s Interesting). As he transitioned to life aboard yet another naval ship, he gained the name most people knew him by: Unsinkable Sam.

The torpedo that hit the HMS Ark Royal decimated the ship, yet Unsinkable Sam survived again, per All That’s Interesting. Sailors on the British Royal Naval destroyer the HMS Legion found the cat among the wreckage. According to official reports, he “was found clinging to a floating plank by a motor launch and described as ‘angry but quite unharmed'” (via ZME Science).

At this point, it’s safe to assume that Unsinkable Sam was at the end of his rope when it came to abandoning ship. What’s more, sailors had to start wondering whether the naval cat represented an omen of danger. After all, sailors tend to be a superstitious lot, so it’s not a far stretch to assume no other ships wanted to house the devastation-prone cat. That said, any objective viewer would also point out that the story of Unsinkable Sam illustrates just how fraught with danger naval activity was in World War II, as explained by Naval History and Heritage Command.

World War II is described as “the first time in naval history opponents engaged out of sight of each other. Radar gave the fleet new eyes, as technological progress improved their defense and added power to the offense” (via the same source). The result? Devastating technological implications for naval ships on both sides. In other words, even a cat with nine lives needed to think twice about long-term life on a naval vessel! After all, there were only so many floating planks out there to hitch a ride on.

Photographic evidence of Unsinkable Sam proves problematic, according to All That’s Interesting. Some have identified one photo showing a black-and-white tuxedo cat as Unsinkable Sam. But if you look closely at the cat’s collar, it includes a name tag reading “HMS Amethyst 1949.”

For this reason, researchers have identified it as a photo of Simon, the Amethyst’s wartime mascot. There’s also a third photo of a cat on a battleship that is widely thought to be Unsinkable Sam. The issue is that the cat is a tabby, which doesn’t fit 99% of the anecdotes about Sam. However, these cat photographs do point to the fascinating prevalence of marine cats in military service. Just how popular were cats on ships? Despite the belief that cats and water don’t mix, traditional sailors used them for centuries to keep down rat numbers. This practice dates back to ancient Egypt. 

According to Naval History, “Without the presence of cats, a crew might find their ship overrun with rats and mice that would eat into the provisions, chew through ropes, and spread disease. Superstitious sailors believed that cats protected them by bringing good luck.” Not only did crew members bring cats from their homeland on travels around the world, but they also picked them up in foreign ports. Besides catching mice and rats, sailors reportedly also harnessed cats’ night vision to help detect the distant lights of shipwrecks at night.

Pets haven’t just accompanied sailors in war. Domesticated canines and pigeons have also long been a presence in war zones on land. Like cats, these animals promoted troop morale. What’s more, pigeons and dogs also served on the front lines, according to All That’s Interesting. Stubby, a tough-as-nails Boston terrier earned a reputation as one of the most notable mascots in the military. Smuggled onto the frontlines by his owner, Stubby soon rose to the ranks of the squadron’s mascot. How did he earn his keep during wartime? He warned troops of surprise attacks and helped rescue the wounded with his highly attuned nose.

Pigeons, particularly messenger pigeons, were used for relaying messages. And the array of pets didn’t end there. Some soldiers even resorted to domesticating wild animals including bears, mice, monkeys, and chickens, according to All That’s Interesting. In each case, these animals helped keep soldiers’ spirits high. They also provided comfort and a way for troops to take their minds off the carnage going on around them.

But even if the story of Unsinkable Sam is untrue or inaccurate, it provides a reassuring message. According to ZME Science, “As for Sam’s legacy, it goes to show that even in the most dire of circumstances, even as everything around you is crumbling down, you can still cling on to a piece of wood, get rescued, and move on to another ship and start over again. Or it goes to show that cats really do have nine lives — all of which are absolutely worth living.”