In which George Orwell novel does the character of Old Major appear?

Old Major (also called Willingdon Beauty) is the first major character described by George Orwell in Animal Farm. This "purebred" of pigs is a kind, grandfatherly philosopher of change.

Old Major proposes a solution to the animals' desperate plight on Manor Farm under the Jones administration and inspires thoughts of a rebellion. The actual time of the revolt is unsaid; it could be tomorrow or several generations down the road. Old Major dies three days after delivering his speech and the animals, stirred up by this speech, set to work immediately on the bringing about of the Rebellion.

Shortly after his death, the animals rise in revolt and oust the humans from power. This rebellious act is so quick that many do not realize it has happened until it is over. The animals drive Jones and the farmhands off the farm and remove many of the implements of his rule.