Basil, also referred to as Basil the Great Mouse Detective and Basil of Baker Street, is a fictional character created by Eve Titus. He is a mouse version of Sherlock Holmes who lives in Victorian London.
Basil is a tall, thin, tan furred mouse who often wears a deerstalker and hunting cape. He has an educated British accent. He also wears a number of disguises.
Basil is excitable and is given to dramatic outbursts as well as sudden low spirits. He is highly intelligent and capable of intent concentration to the point of being oblivious to everything else around him. A brilliant detective, he is energetic and tenacious when pursuing an evil do-er, assisted by his friend Doctor Dawson and the bloodhound Toby.
Basil was pursuing Professor Ratigan when Doctor Dawson brought him Olivia Flaversham, whose father had been kidnapped by Fidget the bat on Ratigan's orders. Their investigations led them to a waterfront bar and the hidden entrance to Ratigan's lair, where they were ambushed. Ratigan left Basil and Doctor Dawson in a death trap, but Basil was able to escape and rescue everyone. They were able to foil Ratigan's plans but Ratigan took flight. Basil and the others pursued and finally fought Professor Ratigan on top of Big Ben, where the latter fell to his death.