snowball-
Snowball is the real allie and can earn the trust and loyalty of the other animals.  Napoleon disagrees with snowball about building the windmill, Napoleon chased Snowball off the farm and then decided to build the windmill.
Boxer-
Boxer was a loyal and hard worker on the farm. He believed that the pigs were always right and he could always work harder. He didn’t know how much he could take and wouldn’t stop working but then when he fell Napoleon sold him to the slaughter house for money to buy more whiskey for the pigs and lied to everyone and said he sent Boxer to the vet and he died there.
Mollie-
Mollie was a horse who represented the bourgeoisie and she didn't want to do any of the work on the farm. Mollie liked the old ways of the farm when she got to wear ribbons and get attention from the humans.
Squealer-
squealer spreads Napoleon’s propaganda and makes all the bad things that Napoleon sound good. Squealer spreads false information to the rest of the animals about Napoleon.