Writer Seymour Reit and artist Joe Oriolo's idea for a kids book instead morphed by 1945 into theatrical cartoon shorts across film and television. By 1959, Casper became the central star of the bright and cheerful Harvey Comics line, along with Richie Rich and Lil' Audrey. Based off of animation styles, Art Director Warren Kremer created the instantly recognizable house look for all Harvey characters, a stylized world of rounded bodies, clear space, spot-color covers, pastel-toned pages, and clean bold lines.
The original premiere cartoon was darker, with Casper as the ghost of a dead child. Later versions became more family-friendly by channeling him purely as an ectoplasmic creature from another realm. The 1995 film took the risky course of having him as a dead spirit, in order to bring a human gravity and romantic connection to the plot. But along with the gothic tonal skew, the film also kept many of the basic conventions of the spritely Harvey Comics version, including the mischievous Ghostly Trio of uncles. The film did very well for its budget, and video sequels and new cartoon series followed.