Betty

Betty is Dr. Tofu Ono's display skeleton. In the earlier parts of the anime and manga Dr. Tofu is almost never seen without "her" in close vicinity. Not much is known about Betty, other than Dr. Tofu has her stored in the treatment room of his clinic and occasionally will perform practical jokes with her (i.e. having him sneak up behind someone before using Betty's hand to touch their shoulder). In the anime, Dr. Tofu is also shown to imitate a female voice, possibly to make younger patients more comfortable when they arrive for treatment.