Dr. Delbert Doppler is the triagonist in Disney's 2002 animated feature film, Treasure Planet. He is an alien with the appearance of being some kind of dog/human hybrid, and a notable and well-off astronomer. Doppler is also a longtime friend of Sarah Hawkins, and becomes the guardian of her son, Jim Hawkins, during the expedition to find Treasure Planet.Dr. Delbert Doppler is seen as the classic astronomer who trips over his own feet and words yet seems to be one of the smarter characters, despite his choices in fashion. He is relatively pacifistic, not handling weapons if he can possibly avoid it. He is also very kind as he cares for both Jim and Sarah and was more than willing to let them stay at his house when their own inn was destroyed. As a scientist, he loves making new discoveries and exploring which was why he was so excited to explore the map. He can be a bit paranoid considering the suit he wore on his first day out in space. He also is socially awkward as shown through his interactions with Captain Amelia and the crew. He doesn't take kindly to insults, as shown when Captain Amelia insulted him. Deep down, he feels he is useless as he couldn't fight, didn't know how to properly attend to Captain Amelia's wounds, and couldn't find a way to help Jim and Captain Amelia when the crew betrayed them. However, he is very brave and loyal, managing to protect his friends and stand up to the bad guys when the situation called for it. He is also fairly intelligent, which has proven useful during the time the crew was stuck in the middle of the black-hole and his research and predictions of the outburst of the black hole allowed Captain Amelia a way to pilot out of the black-hole, which she commended him for.