More on “graphic novels”, now in the person of Raymond Briggs, who straddles illustrated comic books for children and graphic novels (in the broad sense) for adults:
Raymond Redvers Briggs (born 18 January 1934) is an English illustrator, cartoonist, graphic novelist and author, who has achieved critical and popular success among adults and children. He is best known for his story The Snowman, which is shown every Christmas on British television in cartoon form and on the stage as a musical. (link)
… His first three major works, Father Christmas (1973), Father Christmas Goes on Holiday (1975) (both featuring a curmudgeonly Father Christmas who complains incessantly about the “blooming snow”), and Fungus the Bogeyman (1977), were in the form of comics rather than the typical children’s-book format of separate text and illustrations. The Snowman (1978) was entirely wordless, and illustrated with only pencil crayons.
… Briggs continued to work in a similar format, but with more adult content, in Gentleman Jim (1980), a sombre look at the working class trials of Jim and Hilda Bloggs, closely based on his parents. [A successor book with the same principal characters, When the Wind Blows (1982), took on global nuclear war.]
On his deliciously dirty Fungus:
Fungus the Bogeyman (1977) is a children’s graphic novel by British artist Raymond Briggs. It follows one day in the life of the titular character, a working class Bogeyman with the mundane job of scaring human beings. (link)
In a quite different vein, the touching Ethel and Ernest:
Ethel and Ernest (subtitled “A True Story”)  is a graphic novel by English author and illustrator Raymond Briggs. It tells the story of the lives of Briggs’ parents from their first meeting in 1928 to their deaths in 1971. (link)