Superhero coloring pages - what could be finer?
We have Batman and Robin and Superman and The Flash and Aquaman and Wonder Woman and Invisible Woman and Spiderman and Black Widow and Wolverine and Captain America and more.
Superheroes began in the 20th Century, though you could make the case that folklore characters such as Robin Hood were superheroes. They started gaining steam during World War II, when Captain America became a propaganda tool for the US government.
Superheroes generally have some kind of super power, such as great strength or the ability to become invisible. They also are righteous, fighting for the good of others, which distinguishes them from the bad guys. They usually like to be anonymous and do their good deeds at night. Something in their past usually drives them to fight crime and support society, not seek their own personal gain. They also have some help, whether it be a side-kick like Robin or a collection of others with superhero powers such as the Avengers.
Villains are necessary if you have a superhero. For instance, Superman faces Lex Luther, and Batman confronts the Joker and others. The superhero usually has some vulnerability that must be overcome, such as kryptonite for Superman. However, in the end, the superhero invariably triumphs.