A rare, repeatable achievement for completing a quest in an unusually clever way — it upgrades your quest box.
Hadji! is a rare, repeatable achievement Carl (and Princess Donut) earned for completing the circus quest in an unusual way, upgrading their Gold Quest Box to a Platinum Quest Box; Mordecai notes an even higher tier exists that double-upgrades the prize. It came bundled with other quest achievements — 'Johnny Quest' (completing a quest without dying, unlocking occasional quest-location map markers) and the mocking 'Yellow-Bellied Chickenshit' (surviving a boss battle without a kill, 'pussies don't get prizes'). Reaching the third floor Carl amassed over 20 achievements at once, his most ever.
Achievements rewarding Carl's clever, non-lethal quest resolution.