The chief way Doyle creates an "Oriental other" is through the mysterious character of Tonga, a tiny Pygmy-like man from the Andaman Islands in the Bay of Bengal, near India. Tonga's description is "other": he is called a "savage" and a "cannibal." He seems more animal-like than human. He has, writes Watson, a "misshapen" head and is so "distorted" that Watson whips out his gun. Watson describes him as marked with "bestiality" and "cruelty." His eyes "glowed" and "burned," and Tonga "grinned and chattered" with a "half-animal fury."
This shows the "Oriental" as the terrifying other, so different from "civilized" men like Holmes and Watson that Tonga could, Watson states, give a "man" a "sleepless night." With his blow gun and poison darts, he is a creature out of nightmares and Western fantasies of the primitive non-whites who are so threatening they must be subjugated and controlled.
Also, with a "rajah's" treasure of costly jewels at stake, Doyle plays on the idea of the Orient, especially India, as an exotic place of untold wealth, wealth there for Western plunder—and deserved of by Westerners who are not questioned for taking it for their own profit.