* AlternativeCharacterInterpretation: Is Longtarin a poor victim of Gaston or a total JerkAss which deserves Gaston's antics ?
* CrazyAwesome: Some of Gaston's inventions, like the propeller on the roof of his car that recharges the battery: it starts lifting the roof off, so Prunelle grabs, then ''the whole roof lifts off'' and Prunelle is sent on a long flight, ending because of a stupidly-placed wall.
* GrowingTheBeard: Many people found the comics more funny after Franquin created other recurring characters and that the plot doesn't only focus on Gaston and Fantasio.
* HeartwarmingMoment: In one comic, Fantasio shows Spirou what happens when you whisper things in Gaston's ear while he's sleeping. When you whisper things to Gaston that he likes (eating, sleeping) he smiles, but when you say things he dislikes (working, sorting mail), he frowns. Just as Fantasio gets annoyed at Gaston, Spirou whispers Fantasio's name to him, and he smiles even more than when you mention eating or sleeping (see also HoYay). Fantasio is visibly moved, commenting that Gaston is 'a good guy at heart'.
** [[http://spiroureporter.net/wp-content/uploads/2013/12/Gaston-234-695x448.jpg This comic]] about Gaston sneaking in snowballs to work. It's nice to see Fantasio playfully going along with Gaston's game, which is something that doesn't happen very often.
* HilariousInHindsight: Wiki/TheOtherWiki mention that there's a real-life businessman named De Mesmaeker in Belgium. Needless to say, taking him seriously whenever he has to sign contracts isn't easy.
** De Mesmaeker was actually inspired by one of the relatives of Franquin's coworkers, who coincidentally was a businessman. The man took it rather well, to the point of jokingly asking "Where are the contracts ?" while dealing with French clients.
* HoYay: Just a bit. In one comic, it is revealed that Gaston likes Fantasio even better than sleeping. Another features a gag which, in a way, sets them up as a couple -- Gaston swallows the prize inside a box of candy and has to go to the hospital. When the prize is retrieved, a nurse cheerily tells Fantasio, who is waiting worriedly in the hallway, [[MisterSeahorse "It's an airplane!"]] And then there's a comic in which Gaston surprises Fantasio by throwing paper confetti snippets on him for his birthday. He explains that it's a tradition Americans do for the people they love.
* StrawmanHasAPoint: One strip has Prunelle chewing out Gaston for napping with the cat sleeping on his lap while the others are working. He gets to work, retorting that if every dictator, general etc. would do just that once in a while, he'd feel a lot better. Prunelle's thoughts: "What do you reply to a guy who's right?"
* WhatAnIdiot: Gaston comes up with a simple system to pollute less: fitting a giant balloon to his ar's tailpipe, ensuring that the toxic fumes don't escape into the atmosphere. And then, of course, he removes it at the end, requiring gas-mask equipped rescuers to intervene to reanimate all the suffocated bystanders.
** An early gag had Fantasio demanding him to take down an enormous balloon he had tied to the office roof. Gaston climbs in the rope with a knife and starts to cut away at it above his head. When Fantasio warns him that he'll fall if he does that, Gaston instead cuts away the rope underneath him, which inevitably leads to the balloon flying off with Gaston still hanging on to it.