War Elephant: Animal Soldier !

A war elephant was an elephant that was trained and guided by humans for combat. The war elephant's main use was to charge the enemy, breaking their ranks and instilling terror. Elephantry are military units with elephant-mounted troops.

War elephants played a critical role in several key battles in antiquity, but their use declined with the spread of firearms in the early modern period. Military elephants were then restricted to non-combat engineering and labour roles, and some ceremonial uses. However, they continued to be used in combat in some parts of the world such as Burma, Thailand, and Vietnam into the 19th century.
Source: Wikipedia