Template:Infobox CharacterBoh is the biological son and only known child of Yubaba and the nephew of Zeniba.
Boh is a large baby that belongs to Yubaba and, up until meeting Chihiro (Sen), has remained within his nursery out of fear of germs. He is treated as an infant by his doting mother, Yubaba. Although a baby, Boh is able to talk, surprisingly, fluently for his apparent young age, and walk. While in his baby form, he is seen only wearing a full-sized, one-piece bib.
During the events of the story, his maternal aunt Zeniba shrinks him into a small grey mouse-like organism. Prior to meeting Chihiro, Boh is a selfish, nasty, and spoiled child. He was used to getting all the attention, gifts and food he wanted from his mother Yubaba. He also developed a fear of germs (mysophobia), demonstrated by his initial hindrance in leaving his nursery. However, his personality quickly changes during his adventures with Chihiro. In his rat form, he develops a strong affiliation with Yubaba's bird, who was turned into a fly-like creature and would often carry him around when they were not riding on Chihiro's shoulder. By the end of these adventures, we see him literally standing up to his mother to help Chihiro.
It is also suggested that, prior to meeting Chihiro, Boh had not been seen walking or even standing up on his own. This is seen through Yubaba's surprise at seeing Boh standing after his return to her with Chihiro and Haku. It can be assumed that he simply became less lazy and more self-sufficient after his adventure.
- "You'll get sick if you go outside. So stay here and play with me."
- "If you go, I'll cry. Then Mama will hear me and Mama will come in here and kill you."
- "Play with me, or I'll break your arm."
- "I'm not afraid of germs."
- "If you make Sen cry, I won't like you anymore!"
- On his bib, it says the kanji for his Japanese name (坊 Bō)
- He is the only person in the world that Yubaba loves.
- In the English version of the film, his name was never said, only shown in the credits.
- He can't tell his mother from his aunt due to them being identical twins.