Some of the most popular and interesting sidekick characters in the superhero genre are Robin the Boy Wonder, Bucky, Toro, Speedy, Kid Flash and Rick Jones. These sidekicks have become popular because they are the junior partners of some of the greatest superheroes ever created, including Batman, Captain America, the Flash and the Hulk.
Batman’s creator, Bob Kane, introduced the idea of the costumed superhero sidekick in Detective Comics #38 in April 1940. Kane chose to introduce a young boy as a partner to Batman as a way of connecting to the reading audience, which was mostly composed of male children and teenagers. This character was named Robin. Robin was a former circus aerialist who was taken in by Bruce Wayne after his parents were murdered and was trained to become a crime fighter. The popularity of Robin led to a new trend of superheroes taking on junior partners.
Not long after the introduction of Robin in DC comics came Bucky and Toro, who were properties of Timely Comics. Bucky Barnes was the sidekick of Captain America, while Toro was the partner of the Human Torch. Bucky was a normal boy trained to fight, just as Robin was, but Toro had the same flaming powers as the Human torch. All three of these young heroes were orphans who needed guidance and were mentored by notable heroes. Later on came Kid Flash, who had the same super speed powers as his mentor, the Flash. Speedy was the sidekick of the Green Arrow and learned to use a bow and arrow almost as well as his teacher. Speedy would later take on the name Arsenal and then Red Arrow.
Rick Jones came along in the 1960s after Timely became Marvel Comics. Rick Jones started out as the teen sidekick to the Hulk. Rick Jones was responsible for Bruce Banner becoming the Hulk and became his partner to make amends. He later became a sidekick of Captain America.
Even Superman had a sidekick named Jimmy Olsen, but this character was not a crime fighter and did not go into battle as a partner to the Man of Steel, so he is in a different category. He was often more comedy relief than a partner. Superman later had a female sidekick named Supergirl.