How does the toad represent Rick Deckard's journey through the novel?

The mechanical toad at the end of the novel again leaves the reader with some ambiguity about Rick’s state of being. When he first sees the toad, his mind immediately returns to the selfish thoughts that he had at the beginning of the book. He desires the money and fame that finding the toad will bring him. Yet, his realization when he finds out the toad is mechanical that all things, even fake things, have their own “lives” seems to be an admission that his experiences of that day have changed the way he understands empathy forever. Dick never allows Rick Deckard to be the hero of the novel. Instead, Dick shows us how his flaws will always be a part of his character even when that character has undergone significant transformation.