Rocket Raccoon, created by Bill Mantlo and Keith Giffen, first apeared in Marvel Preview #7 in 1976. Over the years, he appeared here and there in issues of Hulk and She-Hulk, however he did get his own 4-issue limited run in 1985. He eventually appeared in Annihilation: Conquest before settling in the Guardians of the Galaxy.
Before he was a Guardian of the Galaxy, he was the “Guardian of the Keystone Quadrant,” captain of a ship called Rack ‘n’ Ruin. He originated from a planet called Halfworld, an abandoned colony for the mentally ill. On Halfworld, animal companions were granted human level intelligence to care for the inmates. Rocket was their chief law officer.
While Rocket lacks “super powers,” he does possess all of the normal attributes of a raccoon ( acute sense of smell, sight, hearing and touch). He is also incredibly proficient with various firearms, and is an excellent tactician and leader. It is not uncommon for Rocket to take the lead when Star-Lord is unavailable.
Rocket Raccon is my favorite Guardian.