Snowball is declared a Hero First Class after the Battle of Cowshed. He distinguishes himself in this battle that is a confrontation between the returning Farmer Jones and other farmers, armed with guns and sticks, who intend to take the farm back.
"Leon Trotsky was the military genius who built the Soviet Army and planned the military campaigns that gave victory to the Communists in the civil war that followed the Revolution. He is personified in Snowball, the first-class hero of the Battle of the Cowshed."
"With the Battle of the Cowshed, Orwell has combined several events from the closing years of World War I and years immediately after the Russian Revolution."
Snowball is fearless in his assault on the humans. He spent time studying the military campaings of Julius Ceasar, therefore he is knowledgeable on battle strategy.
During the Battle of Cowshed, Snowball launched the first attack. His strategy included a second wave attack which was designed to really assault the humans and force them to flee the farm again.
Snowball launched the second line of attack, along with Benjamin, Muriel and the sheep, they rushed forward and prodded and butted the men from every side." (Orwell)