how did the animals intend to commemorate their fallen comrades?

They invent a military honor called “Animal Hero, First Class,” which they bestow upon Snowball and Boxer. Then they bury the fallen sheep and confer upon him posthumously the title of “Animal Hero, Second Class.” The animals decide to call this conflict the Battle of the Cowshed. The agree to fire Mr. Jones’s gun into the air twice a year, on the anniversaries of the battle (October 12) and of the Rebellion (Midsummer’s Eve).