Groot once lived peacefully on his homeworld, Planet X, until Ronan invaded to take the planet for his mining operation. When the natives refused to give up their world, Ronan destroyed the inhabitants; with Groot as the only survivor. Groot managed to save his planet's World Pod that could restore his race. Groot was then forcefully taken to Halfworld by the Ravagers where he met Rocket. The two managed break free and escape whilst freeing the animals that were being experimented on.
Groot is an sentient alien plant who has a limited vocabulary, but his teammate Rocket is the only one who can understand him. He can grow into a giant humanoid tree like being with superhuman strength. He is a leading member of the Guardians of the Galaxy alongside Star-Lord, Drax the Destroyer, Rocket Raccoon and Gamora and Nova.
The Guardians battle the Chitauri an alien race led by Korvac. When Rocket Raccoon's ship is pulled into the Chitauri ship, Rocket fakes surrender so that they can free the captive Guardians of the Galaxy members. Afterwards, Spider-Man discovers that the Chitauri are planning to destroy the Earth. The Guardians plan to run the Chitauri ship into the sun while fighting the Chitauri forces. When their tactic does not work, the Guardians end up making their way towards the Dark Matter Cannon. While Nova and Spider-Man head to the Dark Matter Cannon, the Guardians fight the Chitauri and Korvac. After Korvac is defeated by Groot, Nova destroys the Dark Matter Cannon and the Chitauri ship is destroyed.
Meeting The Avengers
When Galactus arrives to consume Earth, Iron Man ends up having to speak with him which results in both of them teleporting away. The Avengers track Iron Man to the planet where the D'bari live and witness their ships in the middle an evacuation after Iron Man who was empowered by the Power Cosmic led Galactus here. The Avengers had to work with the Guardians of the Galaxy to keep Galactus from consuming Earth. It later turns out that the planet that Galactus was consuming was becoming unstable before Galactus arrived. Galactus found himself unable to stop the process as the Power Cosmic-empowered Iron Man quotes "Galactus must feed." After the planet exploded, Galactus was knocked out cold, the D'bari settled on another planet, and Iron Man returned to normal. 
Star-Lord tried numerous times to convince Tony Stark and the Avengers to give them the Infinity Stones they had been collecting since they arrived to the Earth. When Black Widow took the Stones from their vault in the Avengers Tower with the help of Thor, the Guardians teleported to Earth and intercepted them, with the intention to force them to hand in the stones.
The rest of the Avengers arrived to help. Falcon managed to modify the Guardians' own teleporters, and send them back to their ship. The teleporters had been infected with malware so they couldn't function later.
The Guardians later returned to Earth when Thanos was defeated to the Avengers, and the Mad Titan was handed over to them. In addition to thanking the Avengers for dealing with Thanos, the Guardians apologized for having tried to attack them.
- Late actor Michael Clarke Duncan recorded his lines for Groot in his first appearance shortly before his death in September 2012. According to Brian Michael Bendis, this was Duncan's last job. Kevin Michael Richardson replaced him.
- 10 appearance(s) of Groot (Earth-12041)
- 12 image(s) of Groot (Earth-12041)
- 2 quotation(s) by or about Groot (Earth-12041)