Sergeant Stubby was an American dog that served as the mascot for the 102nd Infantry, 26th Yankee Division in the US Army in World War I. In 1917, he was smuggled overseas to France by his owner, Private J. Robert Conroy, where he won over a commanding officer with his impressive ability to salute. He was injured in a gas attack, but managed to make a full recovery. He would later use his knowledge of deadly gases to warn the sleeping troop of an attack before the alarms could sound, saving countless lives.

Stubby would also track down injured troops in the trench, listening for English words and barking to alert nearby medics. His most astounding achievement was the capture of a German spy, whom he caught making a map of the allied trenches. He managed to subdue the soldier with bites to the legs until troops showed up. After the incident he was given the rank of sergeant, the first animal in the Untied States to receive and official rank.

He retired after an injury from a grenade blast put him in the hospital. By the end of his career, Sergeant Stubby had served in 17 battles, won numerous commendations, and met with three different presidents. His body is kept in the collection of the National Museum of American History.

Sergeant Reckless started her life as a racehorse in Korea under the name Ah Chim Hai, a name that translates to “Flame of the Morning.” She was purchased by Lieutenant Eric Pederson, who recruited her into the Marine Corps under the Recoilless Rifle Platoon, Antitank Company, Fifth Marine Regiment. Her duty was to carry hefty weapons and ammunition, but she would soon be known for her exuberant personality.

She loved attention, and was known to enjoy some beers with her fellow soldiers. Reckless had the freedom to wander camp and had a reputation for eating anything offered to her, but her favorite meal may well have been scrambled eggs and Coca Cola. Sergeant Reckless performed bravely in the Korean war, and did far more than an ordinary beast of burden. She helped lay down communication lines and was extensively trained for frontline combat situations. Eventually, she was promoted to staff sergeant and would retire with full military honors.

G.I. Joe was an American carrier pigeon responsible for saving the lives of an estimated 1,000 men during World War II. During an attempt to take back the German-occupied town of Colvi Vecchia, Italy, American bombers were prepping to unleash a payload to support British troops on the ground. However, and unexpected German retreat meant the British could take the village ahead of schedule.

The problem was, no one could get a message to the Americans about to bomb the whole town. As a last ditch effort, Joe was sent back to the base with a message to stop the bombing. Beyond anyone’s predictions, Joe was able to fly the 20 miles back to base in just 20 minutes. He arrived just before the planes were scheduled to take off, earning him the Dickin Medal for animal gallantry, the only American animal to receive this British commendation.

Jackie the baboon served his country in the trenches of World War I after being shipped out with the 3rd South African Infantry regiment. He was originally the pet of Private Albert Marr, a young South African man who joined the military and asked if he could bring Jackie with him. Jackie partook in drills like any other soldier, and was so respected for his good behavior he was made the official mascot of the unit.

He was given a proper uniform, trained to salute and rest at ease, and was even used as a late night watchman. His acute hearing allowed him to warn the regiment of nearby enemy movements. When Private Marr took a bullet to the shoulder, Jackie stayed by his side and even licked the wound in an attempt at some simian first-aid. His military service would come to an end when he was wounded by shrapnel during an enemy bombing run while trying to build a small stone wall for protection. One of his legs would be amputated, but Jackie and Private Marr would both survive the war. Back home, the duo worked with the Red Cross to help raise money for injured troops.

While it may seem like keeping a live bear as a pet isn’t the best idea in the world, that thought didn’t stop a group of Polish soldiers who purchased a baby bear in a market in Iran. Wojtek was raised by the soldiers and was socialized to humans at an early age. He was adopted into the 22nd Artillery Supply Company of the Polish II Corps, where he was on the official roster and even received military rations.

He was known for his love of beer and eating unlit cigarettes, and his presence was a massive morale booster for the weary soldiers. It wasn’t all games for Wojtek as he served in several battles in Italy, carrying shells and supplies for his regiment. After the war Wojtek would spend the remainder of his life at the Edinburgh Zoo, where he would be regularly visited by the men who raised and served with him.

Siwash was a duck from New Zealand, pictured above standing on the remains of a Japanese bunker, who served with the US Marine Corps in World War II. Amazingly, she was wrongly assumed to be a male during her time as a marine. Her wartime prowess was documented with a full page spread in Life magazine. It is unclear exactly how Siwash joined the First Battalion of the Tenth Marines, but the story goes that she was won by a marine in the unit during a game of poker.

She is most famous for her actions on the island of Tarawa, where she engaged in bill-to-beak combat with a Japanese rooster. Although she sustained injuries to the head, she managed to drive back the enemy and help secure the beach. She received many honors for her bravery, including a purple heart, and would eventually retire at the San Diego Zoo.

Sergeant Bill was a Canadian goat that served as a member of the 5th Canadian Battalion, and was shipped out overseas to fight in World War I. A family in Saskatchewan gifted the goat to the battalion after they traveled through town on their way to a camp in Quebec. The men smuggled Bill on the S.S. Lapland, and was a nuisance to some of the officers while stationed in France. He was put under military arrest twice, once for eating some important documents, and again for charging a superior officer.

He regained favor amongst the brass after successfully capturing a Prussian soldier at the second battle of Ypres, and was eventually granted the official rank of sergeant. His war record was superb as he managed to save three human lives and survive countless injuries, including shrapnel wounds and trench foot. He would received numerous medals and commendations for his actions, and would eventually retire back in Saskatchewan with the family he came from. Today, his body is memorialized in the Broadview Historical Museum, still wearing his dress blues.

This feline served on the British naval vessel HMS Amethyst during the Chinese Civil War. He was awarded the Dickin Medal for his instrumental role in a three month siege that occurred in the Yangtze river in 1949. Originally found as a stray in Hong Kong, Simon was smuggled aboard the Amethyst and quickly bonded with the ship’s captain. He immediately set to work on killing the rat infestation that had been plaguing the ship.

Unfortunately, Simon was badly wounded when the Amethyst was bombarded by communist Chinese troops. After receiving medical treatment for his wounds, he would begin to recover. Eventually, he killed a giant rat nicknamed “Mao Tse Tung,” earning him a promotion as an Able Seaman. For defending the crews food supply from the most deadly of beasts, and allowing the crewman to survive a full three months under siege, Simon became the first and only cat to receive the Dickin Medal. He would pass away shortly after returning to shore in England, and Time magazine would write a tribute in his honor.

When the S.S. Van Warwyck came under attack in World War II, Judy did her best to guide the crew to safety. She was a dog from Hong Kong who had been taken as a mascot for the British naval vessel, and she helped her crew find fresh water and stay alive for two days while they were all stranded on an island in the South China sea. They would escape using commandeered boat, but would soon find themselves in the heart of a Japanese village.

Judy and the crew were sent to a POW camp, where they would spend the next three years living under harsh rule. The beatings were frequent, even for Judy. She risked her life defending the prisoners of the camp from assault, often pissing off the Japanese soldiers enough for them to turn their full wrath on her. The only reason she wasn’t killed was her adoptive owner, a soldier named Williams, who convinced the drunkard Japanese commandant to grant Judy official POW status. Even with her newfound legal status, Judy would still get into trouble. She would bark at the guards, wild tigers, and once got into a battle with a crocodile. After the war, Williams smuggled her to England where she lived the rest of her life as a war hero.

In 1914, a Canadian military veterinarian by the name of Harry Colebourn was headed to the battlefields of World War I. Before he left port, he bought a bear cub for a mere $20 and named her Winnipeg after the Canadian city. He then smuggled “Winnie” on a boat to France, and she immediately became popular with the troops in camp. She boosted morale and was said to be a proficient navigator, but the dangers of trench warfare meant Colebourn had to make a tough decision.

He took her to the London Zoo, where she remained a staple exhibit for 20 years. Children were allowed in Winnie’s enclosure and were free to pet and even rider her, as one zookeeper described Winnie as “the only bear they ever trusted entirely.” It was here Winnie met author A.A. Milne and his son, Christopher Robin. The boy fell in love with the bear and inspired his father to write a story about Winnie and Christopher Robin.