Let me imagines a huge rabbit sitting in front of him. What does Lenny think of it, and how do the rabbits words compared to aunt Clara's?

Like Aunt Clara, the Rabbit reminds Lennie how good George has been to him and ridicules what Lennie believes will be his future. Lennie becomes a bit more frustrated with the rabbit than he did with Aunt Clara, the text notes that Lennie became "beligerent." 

"Now Lennie retorted belligerently, “He ain’t neither. George won’t do nothing like that. I’ve knew George since—I forget when—and he ain’t never raised his han’ to me with a stick. He’s nice to me. He ain’t gonna be mean.”