Snowy

With a few exceptions, Snowy never speaks , since he is "only a dog". However, he always manages to communicate well with Tintin, particularly in the early stories. Snowy often adds to the story in notable ways. For instance, Snowy is the only character in Flight 714 to remember that he was abducted by aliens. Snowy has rescued Tintin many times throughout the series.

Like Captain Haddock, Snowy is fond of Loch Lomond brand Scotch whisky, and his occasional bouts of drinking tend to get him into trouble, as does his acute arachnophobia. Snowy is also fond of bones, to the point of being easily tempted, which has nearly let Tintin down on occasion; for example, he once lost a message from Tintin because of a bone.

The character of Snowy evolved through the course of the Tintin series, and was most dramatically affected by the introduction of Captain Haddock in The Crab with the Golden Claws. Before Haddock's appearance, Snowy was the source of dry and cynical side-commentary, which balanced out Tintin's constantly positive, optimistic perspective. When Haddock entered the series, the Captain took over the role of the cynic, and Snowy gradually shifted into a more light-hearted role, serving to create comic relief by chasing the Marlinspike cat or by drinking the Captain's whisky. Milou was named after Hergé's first girlfriend Malou (a contraction of the name Marie-Louise), although the character is referred to as male throughout the books.

The 1939 Portuguese edition of Tintin in the Congo, renamed as Tintin em Angola, was locally colored and had a yellow female Snowy, renamed Rom-Rom.