[Richard Kimball]

Watterston took inspiration from quite a few sources, but I believe "The Secret Life of Walter Mitty", Little Nemo in Slumberland, and some old Chuck Jones cartoons were the primary inspirations. Calvin was named after John Calvin and Hobbes after Thomas Hobbes.

[VadeRetro]

For all I know, Watterston never read The Other--or saw the movie based on the book--before starting Calvin and Hobbes. I was joking, except that both indeed present a person's fantasy/delusion as story narrative. As you point out, that's really an old device.