In 1942, a Japanese plane, launched from a submarine, dropped two incendiary bombs on a forest in Oregon, which were quickly suppressed but spurred the Forest Service to start a campaign to raise awareness of forest fires. The characters from Bambi, which contains a forest fire scene, were the first, um, spokesanimals in the campaign, but Disney only released them for a year, so in 1944 a new mascot came to life: Smokey Bear.
In 1950, a game warden in New Mexico saved a real bear cub from a fire. He was named after the cartoon mascot, and from there Smokey's fame grew. In addition to posters, stamps, dolls, radio spots, and even a pop song (called "Smokey the Bear" for musical reasons, it created confusion that still persists), Smokey was in a series of comic books.
This tattered copy (which you can read in full here) was first published in 1960, but this reprint is from 1969. The inside back cover has a letter from Smokey to kids, but the back cover suggests "crush your smokes," so kind of a mixed message there.
Now he even has his own website where he exhorts the kids to "Get Your Smokey On."