We are not making this up: In WWII, a Polish unit had a bear mascot — eventually “drafted” — that carried shells for them and, on occasion, fought Nazis. Said unit still exists, and its insignia now memorializes said bear (at right).
On duty, Voytek was trained to carry cases of ammunition and mortar shells down the line to waiting artillery, each one weighing hundreds of pounds. On one occasion, he wandered into an empty shower stall and surprised an Arabic spy who had been listening in on top secret information. The spy quickly surrendered and immediately confessed to all of his crimes, probably because he was smart enough to realize that any military unit possessing Anti-Espionage Bears are likely going to be on the winning side of the war.
After the war, he retired to a zoo in Edinburgh, where he was frequently visited by his former comrades. He died in 1963.
(The first link is a random blog, but he’s also in Wikipedia, for crying out loud.)
There were also Romans in ancient times that would light Pigs on fire and send them screaming into a mounted elephant unit, thus scaring the crap out of said elephants, rendering them useless.
Yeah my Molossers were used by the Greeks, Romans, and some guy named Hannibal who invaded Rome. Spikes, chain mail, burning coals and slobber. Though the bear is pretty cool. Guess they blamed the smell on that darn Voytek.