Esther is (or was) a female sentient mouse.
Appearances[]
Esther was only cited in the unofficial short story The Professor's Portrait by FantasmaTraNoi, which can be read here.
Description[]
Not much is known about Esther. She originated from the same village as Basil of Baker Street, and Basil mentioned once that Esther was one of the only mice whose company he did not mind during his childhood, and the only one who didn't mock him for his incessant musing and love of science and knowledge.