He is generally seen as a more "modern" character, as opposed to the older archetypes (crusty sea captain, absent-minded professor) that inhabit Hergé's earlier works.
Jolyon Wagg is based on a salesman who actually once came to Hergé's door and invited himself in, but also on a stereotype of what Hergé called a “Belgician” (roughly, "an Ugly Belgian", one who is insensitive, for example, when visiting in foreign countries). Wagg appears late in the series, starting with The Calculus Affair, where his self-importance and insensitivity enrage Captain Haddock. Wagg also appears in The Red Sea Sharks, The Castafiore Emerald, Flight 714 and Tintin and the Picaros.
Wagg appears three times in The Calculus Affair, inviting himself inside Marlinspike Manor, interfering with a critical radio transmission, and moving into the Marlinspike Manor with his family for the vacation while Tintin, Haddock and Calculus are gone. Tintin, who rarely shows anger anyway, is unaffected, however the Captain is goaded into memorable rants, for example:
Wagg’s status changes somewhat two albums later when he has apparently been invited inside by Captain Haddock in The Castafiore Emerald. In the final Tintin album Tintin and the Picaros the tables are turned when Tintin and the Captain steal the costumes from the group Wagg is travelling with.
Wagg has an unusual role in Tintin albums in that, unlike most recurring characters with a role in the plot, he’s a relatively average human being. (Not being criminal, eccentric, dictatorial or famous.) He facilitated Hergé's bringing in a more realistic, domestic mood into some stories. Perhaps reflecting Hergé’s dislike of mediocrity, in his appearances Wagg never accomplishes much, except to get in the way.
Names in Tintin are not always literally translated (for example "Tintin" is what’s said in Belgium when touching toast glasses together before drinking), and humor behind Séraphin Lampion is not conveyed into English. Rather, another joke is used (a prevalent practice in Asterix English translations). This name translation, while not as clever as the original, was apparently okayed by Hergé, who worked closely with the English translators. What Hergé intended in French is not possible to translate directly, however he "wanted something 'puffed up', a tone which expressed at the same time fleshy and weak." Wagg’s original French name, Séraphin Lampion, is a contrast between the first name meaning seraphim, and the last name meaning a "chintzy little lamp of the sort Wagg would use to decorate his home" , or perhaps alternately "a show off". A range of meanings may have been implied.