A young boy staying at the Mountain View Inn who befriends Ralph and shares his love for toy motorcycles, forging a unique friendship with the talking mouse.

Keith's parents, who stay at the hotel with him and occasionally clash over issues like the presence of mice, subtly challenging Keith's secret friendship with Ralph.

An experienced and kindhearted hotel staff member who discreetly supports Ralph's escapades, aware of the mice's ability to talk.

A cautious and protective mouse who worries over Ralph's adventurous tendencies, struggling with the family's safety and survival.

A mouse with a flair for the dramatic who inadvertently complicates Ralph's life with his bragging but gradually comes to respect him.

A mouse who prides herself on living in a nicer part of the hotel yet depends on human food scraps, often voicing her skepticism about humans.

A small dog residing in the hotel that poses a threat to Ralph but ultimately becomes an unexpected part of Ralph's adventure.

A hotel employee who unwittingly disrupts Ralph's life with her cleaning, setting off a chain of events that affect the mouse community.