There are two kinds of airlines: the dead serious, and those prone to a little fun. The latter sometimes takes the form of eccentric special paint jobs (American’s flying some planes in TWA livery to honor the past; Eva Air runs Hello Kitty-themed planes, etc.)
And now, Brussels Air has kitted an A-320 out with a huge Tintin cartoon that looks as if it’s a cartoon airplane flying by the real one. It’s based on an adventure of the Belgian cartoon character, and actually represents a submarine. If you want to see it or ride it, you can find it on Brussels Air’s website, HERE.