Casper & Nightmare #21

Harvey's Giant-Size format means extra fun for your money, and this 1968 entry pairs Casper the Friendly Ghost with Nightmare the Galloping Ghost in lively, anything-goes fashion. The cover shows Casper riding atop the spectral horse Nightmare as they charge through an icy landscape, with a pair of wild-eyed red monsters lurking below — and small inset panels along the left edge hint at appearances by Spooky, Wendy, and the Ghostly Trio as well. It's a cheerful, charmingly spooky package that captures Harvey Comics at its most imaginative and kid-friendly best.