Snowball is instrumental in forming the teachings of Old Major into Animalism. He is a leader in explaining what the revolution will mean to the animals. He is instrumental in the overthrow of Jones and his hands, he organizes the animals into committees, and he plans, and advocates for, the construction of the windmill, which he envisions as a way to make the farm into a modern, efficient utopia for the animals. Perhaps his most important moment, however, is when he leads the animals in the Battle of the Cowshed:
Snowball now gave the signal for the charge. He himself dashed straight for Jones. Jones saw him coming, raised his gun and fired. The pellets scored bloody streaks along Snowball’s back, and a sheep dropped dead. Without halting for an instant, Snowball flung his fifteen stone against Jones’s legs. Jones was hurled into a pile of dung and his gun flew out of his hands.
In many ways, the battle is Snowball's undoing. His popularity among the animals arouses the jealousy of Napoleon, who uses the attack dogs he has trained from birth to chase him off the farm. At this point, he steals Snowball's idea for the windmill, and denies that Snowball has contributed anything to the farm. Thanks to the propaganda of Squealer, Snowball is recast as the enemy of everything the farm represents, a shadowy figure always trying to collude wiht the humans to destroy Animal Farm.