Explain about Rabbit: What is he? Why is he named this? Who named him? How does Johnny feel about Rabbit? How is this obvious

Uncle Lorne and his wife give Johnny plenty of free time, which he spends reading. His only chore—outside of his delivery duties––is to babysit Aunt Lorne’s baby son, whom Johnny nicknames Rabbit. Johnny adores the baby and likes to talk to it when he doesn’t think anyone can hear him. Aunt Lorne sometimes catches him doing this, and thinks to herself that Johnny is lonely.