Who he is: He is Groot.
His power: An intelligent treelike organism, Groot has the power to grow and manipulate his body in a variety of ways. His reflexes aren’t the fastest, but he can shoot out appendages, grow new ones, extend his current limbs to a decent distance, and even create a protective shield around others with it, though that last one doesn’t always work out so well.
His story: Groot’s limited acoustic skills only allow him to say the words, “I am Groot.” A frequent partner of Rocket Raccoon, the two were on Nova looking for bounties at the beginning of Guardians Of The Galaxy, where they are imprisoned after a protracted battle attempting to capture Peter Quill. In prison, they team up with him, along with Gamora and Drax The Destroyer, to capture an orb that turns out to contain an infinity stone. After being attacked by Ronan The Accuser while attempting to collect payment for the orb, they form an alliance with the Ravagers (led by Yondu Udonta) and the Nova Corps to recover the stone, kill Ronan, and prevent the destruction of Nova. Unfortunately, during the crash, Groot is blown apart.
Groot returns in Guardians Of The Galaxy Vol. 2, reduced to an adorable—and merchandising friendly!—baby version of himself. Although he spends most of the movie dancing cutely and getting rescued by his teammates, he does help his captured friends escape from the Ravagers, and eventually assists them in bringing down the evil Ego.
Voiced by: Vin Diesel, and it’s surprisingly affecting.
Currently, Groot is: A surly teenager, refusing all attempts to get him to clean his room.
Where will we see him next? Avengers: Infinity War.