The doctor is an extremely irritable, grouchy old man. He has a passion for inventing, though showing no skill at inventing whatsoever, shown by the following things: Sally was obviously not supposed to be a "good for nothing girl," and the heart, the potion, and the experiment all turned out wrong. In addition, he has somewhat of an ego, repeatedly insisting that his designs and inventions are flawless and finding ways to blame his failures on others, such as a shortage of ingredients for the artificial heart or a need of better assistants to construct The Experiment.