You won't EVER learn about these in history class. Check out these nearly insane tactics that turned out to be brilliant on the battlefield.
The Japanese Jellyfish Bombs, WWII

"Japan launched 6000+ paper balloons attached to incendiary bombs in hopes that they would float across a Pacific airstream and catch American forests on fire. Quite a few made it to the states. It was kept quiet by the U.S. government so almost no one heard about it, except in the Pacific Northwest where mysterious 'jellyfish in the sky' were spotted slowly floating by. One of them landed in Oregon and killed 6, leading to the only deaths from WWII inside the contiguous United States."
The Persian Cat Army, Battle Of Pelusium

"Persian leader Cambyses II used cats to defeat an Egyptian army. He had his soldiers paint cats on their shields and brought hundreds of cats and other animals that the Egyptians held sacred to the front lines. The Egyptians refused to fight the 'cat army' and were easily defeated because of it."
The Razzle Dazzle Ships, WWI

"The British and U.S. navies used razzle dazzle camouflage on their ships to confuse their opponents. Unlike other forms of camouflage, dazzle was used to make it difficult to estimate a target's range and speed. When an enemy ship would look through their periscope to get the coordinates of a dazzled ship, it created such a crazy optical illusion that it was difficult to even determine what direction the ship was heading in and thus impossible to target a torpedo at them."
The Naked Celtic Army, Battle Of Telamon

"The Celts have gone into combat on a few occasions completely naked. It's freaky enough to face off against a large army of big, screaming men decked out in armor and waving swords, but it'd totally f*ck with your mind to see an army of buck-ass nude guys."
Matchbook Trickery, WWII

"The UK air force dropped matchbooks into enemy lines that contained instructions on how a soldier could fake illnesses to get sent home. Once the Nazi leaders caught wind of this, they stopped sending their troops home who claimed to have said illnesses. Not only did this get healthy enemy troops sent home, it also eventually led to genuinely ill troops being sent back into combat and spreading real disease amongst their ranks."
The Campfire Diversion, Mongol Empire

"Genghis Khan was pretty devious. One of my favorite tactics he used was lighting extra campfires to make his armies seem much larger than they actually were."
Cyrus The Great’s Camel Soldiers, Battle Of Thymbra

"Cyrus the Great realized that Lydian horses were afraid of camels, so he re-routed their forces with camel-mounted warriors."
The Homeless Man Decoy, WWII

"During WWII German agents recovered the body of a British Royal Marine pilot from the waters off a Spanish beach. Documents in an attaché case handcuffed to the officer’s wrist provided a goldmine of Allied intelligence, and German agents quickly sent the documents up the chain of command where they soon reached German leader Adolf Hitler. Hitler studied the captured plans carefully, and, taking full advantage of their top-secret details, directed his troops and ships to reinforce the islands of Sardinia and Corsica, west of Italy, against an impending Allied invasion. There was only one problem— the recovered body was actually a homeless man from Wales who had committed suicide and the documents were an elaborate British diversion called Operation Mincemeat. By the time Hitler redirected his troops in the summer of 1943, a massive Allied invasion force was sailing to Sicily."x
Modern Day Beheadings, Afghanistan Battle

"This is a tactic the Gurkhas used in Afghanistan (in the recent conflict there). When they went to attack a Taliban outpost, they'd sneak ahead and kill the outer perimeter guards. Then they'd cut off the guards' heads, and reattach them with sticks. When the guard change happened, the new guards would tap their friends on the shoulder and crap themselves as their friends' heads fell off. Gurkhas are crazy. Awesome, but crazy."
The Viking King Who Played Dead, Norwegian Battle

"Harold Hardrada pretended to die when injured during a siege. Then he had his men ask for permission to bury their leader inside the wall. The city capitulated so long as they didn't bring weapons inside. So Harold climbed into a coffin in full armor, was carried through the gates and when the time was right, burst out of his own coffin, fought his way back to the gates, opened them, and took the city."
The Suicide Scare Tactic, The War Of Wu And Yue

"King Goujian of Yue had a reputation for having the entire front line of his own army kill themselves just to freak out the opposing troops. Some accounts say that he used criminals sentenced to die and that they decapitated themselves, but these two details may actually be a translation error in the original historical account. What a crazy ass way to send the message that you are way scarier than the enemy."
Julius Caesar’s Double Wall Trap, Battle Of Alesia

Caesar laid siege by building a wooden wall with towers, ditches and traps around the entire town. Vercingetorix called upon his allies, and a Gaulish army that outnumbered the Romans marched on Alesia. So, Caesar ordered another wall to be built around the first. Now he had the Gauls surrounded, and was himself surrounded by more Gauls. After days of intense fighting, the Gauls broke through. Caesar took command of the last reserves, threw himself into the melee, and turned the tide. Eventually the Gaulish reinforcements routed, and Vercingetorix threw his shield at Caesar's feet."
The Fiery Pigs That Brought Down A Castle, Siege Of Rochester Castle

"The Romans lit pigs on fire to scare Hannibal's elephants.On the other hand, Hannibal had the balls to march across the alps with f*cking elephants. Flaming pigs were also used in the siege of Rochester Castle by King John of England. He had his troops dig a tunnel under the castle, then herd a load of pigs set on fire into the tunnel. They set fire to the supports and caused the tunnel to collapse, bringing down the castle with it."
The 13 Ships That Took On 133, Battle Of Myeongnyang

"Yi Sun Sin takes the last 13 ships in the Korean navy against a 133 ship strong Japanese navy. By leading his fleet into a narrow strait, which only allowed 10 ships to attack at a time, Yi was able hold his ground for more than 40 minutes. The technologically advanced Korean ships charged and sunk the Japanese leader’s ship, leading to a collapse of Japanese morale and massive casualties. In the end the Japanese left with only 10 of their ships in tact. Not one Korean ship was lost."
The Ghurka Super Soldier, WW2

Bhanbhagta Gurung, pinned, and unable to fire from the lying position, stood up fully exposed and calmly killed the enemy sniper with his rifle, saving his section from suffering further casualties. He rushed on to clear three enemy bunkers and foxholes, killing the Japanese in them with his bayonet and grenades, while under continuous point-blank Light Machine Gun fire from a bunker on the North tip of the objective. He pressed on and lead the charge through the remaining enemy lines.
Inflatable Tanks, WWII

"During WWII the British used tons of inflatable tanks and airplanes as decoys, as well as a bunch of wooden ones as well, and painted them to look like tanks, boats, and airplanes from the air. They're brilliant and silly at the same time."