Comet first appeared in the story "The Legion of Super-Traitors!", published in "Adventure Comics" #293 (Feb 1962) during the period known as the Silver Age of Comics. This story introduced the Legion of Super-Pets, bringing together several previously established super animals. Krypto the Super-Dog came from Superman's past, Streaky the Supercat and Beppo the Super-Monkey from Superman's present — and Comet was presented as a super-pet who came from the future. "Yes, readers!" a caption declared, "This is a PREVIEW GLIMPSE of a super-pet Supergirl will own some day in the future!" The horse was properly introduced seven months later, when Comet met Supergirl in "Action Comics" #292 (Sept 1962).