Gamora first appears in Strange Tales #180 (June 1975).
Gamora is the adopted daughter of the supervillain Thanos, and the last of her species. Her powers include superhuman strength and agility and an accelerated healing factor. She has appeared as the occasional love interest of the superheroes Adam Warlock and Nova, and a member of the group known as the Infinity Watch.
Gamora is the last of her species, the Zen Whoberi, who were exterminated by the Badoon (in her original timeline, her species was exterminated by the Universal Church of Truth). Thanos found the child and decided to use her as a weapon. Gamora was raised and trained by Thanos to assassinate the Magus, an evil alternate version of Adam Warlock. Thanos showed her little kindness during her childhood, but Gamora was very loyal to the man who promised her the opportunity to avenge the death of her family. Gamora became very proficient in the martial arts, earning the nickname "The deadliest woman in the whole galaxy". When she was a teenager, Thanos took her on a trip to Earth. Gamora disobeyed Thanos's orders, and due to this came into conflict with a group of thugs. She was greatly outnumbered, and despite her skills she was defeated and then raped by the assailants. Thanos found her half dead, and in turn murdered all of her assailants and restored her to health, cybernetically enhancing her to superhuman levels.
As an adult, Gamora was sent as an assassin against the Universal Church of the Truth, quickly becoming feared by its agents, the Black Knights. She exacted revenge for the genocide of her race by killing every member of the church involved before the event actually occurred. Gamora met and teamed up with Adam Warlock, who wanted to stop his older version. She even managed to get close to the Magus but failed her assassination in the last second. Together with Warlock, Pip the Troll and Thanos, Gamora fought to escape the Black Knights of the Universal Church of Truth and Magus's Death Squad. She was then assigned by Thanos to protect Adam Warlock, but she became suspicious of Thanos's plans, and was then attacked by Drax the Destroyer.
Eventually the Magus was defeated, but Thanos revealed himself as an even greater threat. Gamora aided Captain Mar-Vell, Drax, and the Avengers against Thanos. Gamora and Pip tried to prevent Thanos from destroying all life in the universe. Gamora attempted to slay Thanos, but he mortally wounded her, and destroyed Pip's mind. Adam Warlock found them, and Gamora warned Adam of Thanos's plans, and Adam absorbed their souls into his Soul Gem. When Adam Warlock died as well, his spirit was reunited with that of his friends in "Soulworld" within the Soul Gem.
Zoe Saldana will play Gamora in the live-action film Guardians of the Galaxy on August 1, 2014.