is a streetwise, 11-year-old Calcutta orphan, who becomes the adopted son of Dr. Benton Quest. Rarely depicted without his bejeweled turban and Nehru jacket, he is proficient in judo, which he learned from an American Marine. The seventh son of a seventh son, Hadji seems to possess mystical powers (including snake charming, levitation, magic, and hypnotism) which may or may not be attributed to parlor trickery. The Quests meet Hadji while Dr. Quest is lecturing at Calcutta University; he saves Dr. Quest's life (by blocking a thrown knife intended for the doctor with a basket lid) and is subsequently adopted into the Quest family. Though slightly more circumspect than Jonny, he can reliably be talked into participating in most any adventure by his adoptive brother. He is voiced by Danny Bravo. In the sequel series The Real Adventures of Jonny Quest, Hadji is revealed to be an Indian prince, and is given the last name Singh.
Hadji's early life was spent with Pasha Peddler.