Mr. Peanutbutter is a fictional character from the animated television series BoJack Horseman. He is a golden retriever known for his cheerful personality and optimistic outlook on life. As a successful actor, he often contrasts with the show's more cynical characters, particularly BoJack Horseman. In the series, Mr. Peanutbutter is depicted as friendly and enthusiastic, often engaging in various adventures. He is married to Diane Nguyen, a human character, and their relationship explores themes of love and communication. His character adds a lighthearted element to the show, balancing its darker themes.