The Evolution of Hulk After the Fantastic Four ushered in the Marvel age of comics in the early 1960s, creator Stan Lee felt pressure to produce another character that could rival their success. Lee - together with artist Jack Kirby - combined aspects of Dr. Jekyll and Mr. Hyde and Frankenstein to create a monster for the nuclear age: The Incredible Hulk. Hulk is the emotional and impulsive alter ego of the withdrawn and reserved physicist Dr. Bruce Banner. As the Hulk, Banner is capable of significant feats of strength, the magnitude of which increase in direct proportion to his anger. As the character himself puts it, "The madder Hulk gets, the stronger Hulk gets!" For half a century, the Hulk has starred in hundreds of comics, had his own TV show and appeared in three movies, including this year's record-smashing Avengers. But it hasn't always been an easy journey: The Hulk has experienced tragedy, drastic shifts in personality and more than one color change. TIME celebrates 50 years of the the big, (mostly) green monster. MORE: Read Richard Corliss" review of The Avengers Next: The Incredible Hulk #1 (May 1962) The Incredible Hulk #1 (May 1962) In the series" first issue, by Stan Lee and artist Jack Kirby, Dr. Bruce Banner was irrevocably changed when he was belted with gamma rays while saving a teenager from a bomb he helped create. Lee chose grey for the Hulk - a color that did not suggest any particular ethnic group. Next: The Incredible Hulk #2 (July 1962)