Basil of Baker Street

Basil of Basil Street was a detective based on the fictional sleuth Sherlock Holmes and the main protagonist in The Great Mouse Detective. His main goal is to get Professor Ratigan behind bars and rescue Olivia Flaversham's father, while simultaneously preventing a royal assassination. There are a few differences between Basil in the book series and in the film version, such as mercurial moods in the latter. He also plays the violin rather well in the movie, whereas the book series stated Basil's violin playing was atrocious-instead, Basil played the flute.

Role in the film
In the film, when Dr. Dawson meets a lost and frightened Olivia Flaversham, desparately searching for Basil to help her locate her kidnapped father, he helps her find Baker Street. Before long, all 3 are involved in a maze of mystery and intrigue, looking for clues and realizing that all clues point to one person--Basil's arch enemy, the nefarious Professor Ratigan. Quick on his feet and in his mind, Basil and Dawson are able to track down Ratigan's hideout when Olivia is kidnapped as well.

Basil's keen and penetrating mind save the day when, after a near coup of the English royalty and a fierce, animalistic battle on Big Ben, he reunites Olivia with her father, and saves England, with only a few scratches and a smile on his face. At the end, he and Dawson become partners.