Groot is one of the main characters in the Marvel saga Guardians of the Galaxy and as the Earth faces an even bigger threat, he and his group join the Avengers in the third installment of the Avengers infinity war saga. While traveling in space, the group led by Peter Quill stumbles upon the wreckage of Thor’s ship and they retrieve him, surprised that he is still alive after spending so much time in space. Thor needs help to get to the planet of the only dwarf who can forge him a new weapon as powerful as Mjolnir was. Rocket and Groot then take their little shuttle and decide to accompany him. When their mission is accomplished, it allows Thor to invoke the Bifrost and Thor, along with Groot and Rocket, land in the middle of the fight in Wakanda. While Groot acts like a jaded teenager (which he is) and plays on his retro console during the whole movie, he really takes part in the fight when it becomes important.