Dr. Waldo Bloom
Dr. Waldo Bloom (sometimes shortened to Dr. Bloom) is a doctor who works at the Mushroom Kingdom Hospital. He only appears in the Nintendo Comics System comic "The Doctor Is In... Over His Head". He seems to hate viruses and has a big microscope.
At the beginning of the comic, Mario and Princess Peach (who is carrying his plumbing equipment) rush to the hospital to handle what Waldo told them would be a plumbing emergency. However, when they arrive, the doctor reveals that he really called because he needs an assistant, and decides to have Mario take the job (as Dr. Mario).
Dr. Bloom gives the two a tour of the hospital before leading them to his lab, where he shows that he has been studying viruses, but they have been multiplying lately; Bloom reveals that the original viruses were under a massive microscope, but, due to them multiplying, he has placed them all in a massive jar. The viruses then escape from their container, introducing themselves as Chill, Fever, and Weird. They then inflict the three viruses they carry upon the trio and escape. Before Mario can chase after them, Dr. Bloom gives him his coat.
After Mario defeats all the viruses and returns to the hospital, Princess Peach reveals that Waldo Bloom went golfing per her suggestion, stating that he wouldn't return until he finishes his game (however, he has made 456 strokes on the first hole and still has not completed it).