The following illustrations by Japanese artist Gōjin Ishihara depict the end of the world, prehistoric man playing pro ball, and sundry scenes from Hell...and they're all out of children's books and magazines! These books definitely weren't bedtime story material.
Check out Pink Tentacle for a larger sampling of Isahara's mad children's art.
[Spotted on Comics Alliance]
Frozen planet (Year X: End of the World, 1975)
Dark star gravity (Year X: End of the World, 1975)
Nostradamus (Psychics of the World, 1974)
Precognition of plane crash (Mysteries of the Body, 1973)
Prehistoric man as modern-day security guard (Prehistoric Man, 1970)
Prehistoric man as modern-day wrestler (Prehistoric Man, 1970)
Prehistoric man as modern-day baseball player (Prehistoric Man, 1970)
Gorgon (Illustrated Book of World Monsters, 1973)
Kappa (river imp), Illustrated Book of Japanese Monsters, 1972
Burning Hell (Illustrated Book of Hell, 1975)