I'm right in thinking that Casper is the ghost of some boy who has died, no? What did he die of? I used to get creeped out thinking about it. Maybe his parents killed him! Maybe his Mom went really crazy and smothered him in his bed. All right, he died in a car crash. Better? For a little background you can visit the Harvey site.

In 1950, as Casper gained tremendous popularity, Paramount expanded the cartoons into an entire television series. Casper quickly became one of the most celebrated cartoon characters on earth.

They still don't tell you how he died though.

"Casper gained tremendous popularity", that's inexplicable. The stories were weak and the point seemed to be "He's a ghost! But a friendly one, not scary!" So you say. The very fact that this little dead boy shows up at all is not reassuring, to say the least. How would you like it if you woke up at three a.m. and there was this friendly wraith hovering around in your room? "Not to worry—I'm a friendly ghost!" "Whew! That's okay then. The spirit of some friendly dead kid, that I can live with."

There is some more discussion of baffling comic book characters at Alicublog.