Who is the old swamper and what does he tell George and Lennie when they arrive at the ranch?

The old swamper is Candy, an elderly ranch hand with a missing hand. When George and Lennie arrive at the ranch, Candy tells them about the boss and the other workers, warns them about Curley's aggressive behavior, and shares some information about the ranch and its operations. He also mentions his aging dog, which becomes a significant part of the story later on.