Lennie is "huge man", which is ironic considering his name "Small". His size is often used in the novel to give him animal like characteristics, such as "huge paws", "bleated" and "with a collar". This suggests that Lennie has little intelligence and is "jes' like a kid". Lennie relies heavily on George for everything from food to looking after his work card. However Lennie really wants George's approval as shown by "Look, George. Look what I done". Lennie needs this approval, as then George will let him tend to the rabbits when they get their dream ranch (this is Lennie's one ambition, as it is the only thing he can remember fluently). Lennie has little understanding of the consequences of his actions, as shown by what happened in Weed and with Curley's wife "I like to pet nice things". He does however have a basic sense of right and wrong, shown by "I done a bad thing", yet still doesn't understand that killing a woman is worse than a puppy. Lennie's death is foreshadowed by Candy's dog being shot (it even happens with the same gun), and again shows the link between Lennie and a animal, as his death is a act of sympathy by George as is the killing of Candy's dog.
George is a restless small man (at least compared to Lennie) who travels and works with Lennie. He is more intelligent and is relied upon by Lennie for everything, a a task he often finds tiresome. George believes that his life without Lennie would be "so easy" and he would be able to "have a girl". George is like a father to Lennie, as he worries about him, shown by "An' don't you fool around. It'll be dark before long". George also relies on Lennie as a companion "I want you to stay with me". George uses Lennies strength to get them both jobs (which at the time were hard to come by). This means people think he is taking something from Lennie. George looks after Lennie because of a promise, which he keeps until the end. He kills Lennie, because he knows that Curley killing him would be worse and more painful fro him. However this is only after he knew there was no hope for Lennie and even then he regrets this decision, as Slim has to convince him "I swear you hadda". George ultimately kills Lennie to protect him, because he…