The Adventures of Tintin depicted as a weak and alcoholic character, but later evolves to become genuinely heroic and even a socialite after he finds a treasure from his ancestor, Sir Francis Haddock (Chevalier François de Hadoque in the original version). The Captain's coarse humanity and sarcasm act as a counterpoint to Tintin's often-implausible heroism; he is always quick with a dry comment whenever the boy reporter seems too idealistic. After he and Tintin find Red Rackham's treasure, Captain Haddock lives in the luxurious mansion Marlinspike Hall (Le château de Moulinsart in the original French). The hot-tempered Haddock uses a range of colourful insults
The Secret of the Unicorn Haddock was "the best realised character" in the story, conversely describing the Bird Brothers as "relatively uninspired villains". They went on to state that "The Secret of the Unicorn"-"Red Rackham's Treasure" arc represents "a turning point" for the series as it shifts the reader's attention from Tintin to Haddock, who has become "by far, the most interesting character". They praised the "truly outstanding storytelling" of "The Secret of the Unicorn", ultimately awarding it a rating of four out of five. Phillipe Goddin commented on the scene in the story in which Haddock relates the life of his ancestor, stating that