One day when visiting Thomson and Thompson at their office, Tintin takes note of a scrap of paper ripped from a can of crab meat among the belongings of a recently drowned sailor. Upon examining the scrap of paper, he sees the name "Karaboudjan" written on it and is then informed that this is the name of the ship where the sailor was employed.
After an unknown Japanese man is kidnapped on his doorstep, Tintin decides to investigate the Karaboudjan, but is immediately captured. While being held captive, Tintin discovers that the ship's cargo of canned crab meat is actually a cargo of opium. Tintin confronts the ship's captain, named Haddock, but discovers that he doesn't know about the smuggling operation, and is being deceived (and supplied with a lot of whiskey) by his first mate Allan. Along with Haddock, Tintin escapes and ends up in Morocco, where they continue their investigation of the smuggling operation.
''The Crab with the Golden Claws'' is the debut of BreakoutCharacter Captain Haddock, who was originally intended as a one-shot character, but ended up appearing as Tintin's ally in every single story after this one, eventually [[EnsembleDarkhorse eclipsing Tintin himself]] in popularity, even in the eyes of Hergé himself.
* AlcoholInducedIdiocy: Most of what Haddock does.
* BigBad: Omar Ben Salaad.
* CharacterDevelopment: When we first meet Haddock, he is a drunk and miserable wreck without a friend in the world and when he joins Tintin, his alcoholism means he causes more trouble for Tintin than he solves. At the end of the story, he is reformed and becomes the President of the Society of Sober Sailors! In later albums, he retains a fondness for the bottle, but is never as weak or unstable as he is here.
** The drawing of the figure for Haddock in this comic looks a bit amateurish in some cases as well, fitting this characterization. [[ArtEvolution This improves a lot in later comics]].
* ChekhovsGun: The can Snowy gets his nose stuck in turns out to be very important later on.
* CounterfeitCash: Thomson and Thompson are investigating counterfeit coins that they found on the drowned sailor at the beginning of the book, but this doesn't really amount to anything.
* TheDragon: Allan to Omar ben Salaad.
** [[spoiler: DragonTheirFeet: After Salaad is dealt with Allan tries to escape and Tintin has to chase him down by boat.]]
* FalseFriend: Allan to Haddock. Rather depressingly, Haddock calls him the only true friend he has when we first meet him.
* FramedForHeroism: At one point, a raging Haddock charges ahead against a group of armed Bedouin raiders, who promptly run away. It turns out they were actually running away from the reinforcements arriving behind him.
* TheHeavy: Allan.
* HeroicBSOD: Haddock enters one when he realizes he and Tintin are stranded in the middle of Sahara and will probably die of thirst.
* HeroOfAnotherStory: The Japanese police agent who is kidnapped.
* LighterAndSofter: The animated adaptations in comparison to the original comic book story. In at least the Remastered version of the 1990s animated series, Allan's crimes are changed from smuggling opium to smuggling diamonds. But, oddly, only in the second episode; the first episode is true to the comics by having Allan be involved in drug-smuggling, and despite the fact Allan appeared as part of the opium-smuggling ring in ''Cigars of the Pharoah''.
* MadnessMantra: When he enters his HeroicBSOD, Haddock can only repeat the words "land of thirst" over and over.
* MeatOVision: After wandering around in the desert with Tintin for a while, Haddock envisions Tintin as a huge bottle of champagne and nearly strangles him to death trying to uncork him.
* TheMillstone: Haddock.
* PetTheDog: After the Japanese appeared solely as villains in ''The Blue Lotus'', here we get a heroic Japanese character, albeit mostly off-camera.
* RedHerring: The CounterfeitCash subplot at the beginning of the story basically amounts to this.
* ShootTheMessenger: Non-lethal punching variation with Allan.
* VillainWithGoodPublicity: Omar Ben Salaad.
* UnstoppableRage: Haddock gets truly pissed off when a band of Bedouin raiders firing at him shatter his bottle of whisky.