Groot is a character appearing in American comic books published by Marvel Comics. Created by Stan Lee, Larry Lieber and Jack Kirby, the character first appeared in Tales to Astonish #13. An extraterrestrial, sentient tree-like creature, the original Groot first appeared as an invader that intended to capture humans for experimentation. The character can only say the repeated line "I am Groot", but has different meanings depending on context. In the Marvel Cinematic Universe, Star-Lord, Thor, Rocket Raccoon, Gamora and Drax the Destroyer are able to understand him.

Jack Kirby was an American comic book artist, widely regarded as one of the medium's major innovators and one of its most prolific and influential creators. He grew up in New York City and learned to draw cartoon figures by tracing characters from comic strips and editorial cartoons. He entered the nascent comics industry in the 1930s, drawing various comics features under different pen names, including Jack Curtiss, before settling on Jack Kirby. In 1940, he and writer-editor Joe Simon created the highly successful superhero character Captain America for Timely Comics, predecessor of Marvel Comics. During the 1940s, Kirby regularly teamed with Simon, creating numerous characters for that company and for National Comics Publications, later to become DC Comics.