Quill/Chricton - Only human. Taken from Earth suddenly and unexpectedly. Mother died of cancer which is a burden he still bares. Has audio device as only connection back to Earth. Source of constant pop-culture references that are not understood by his companions. Is the "heart" of the group that unites them together. Has plans dismissed by the others around him. Rogue with a heart of gold. Is in possession of a great weapon but only uses it at the last moment. Inept but lovable.
Gamora/Aeryn - Member of the group hunting Quill/Chricton but ultimately turns against. Soldier born and bred. Tries not to let her guard down but is ultimately emotionally disarmed by Quill/Chricton. Forced into battle against her relative who is still working for the group hunting Quill/Chricton and is derided as being weak by that relative.
Drax/D'Argo - Seeks revenge against the group hunting Quill/Chricton for the murder of his wife and loss of his daughter/son. Prone to fits of rage and has a tendency to take things literally. A fan of body art.
Groot/Zhaan - Plant based. Mostly serene by capable of surprising amounts of violence. Unique body chemistry miraculously produces solutions to problems presented by the crew. Sacrifices self to save the crew, though capable of being resurrected if placed in dirt.
Rocket/Rigel - Practical and self-serving. Is motivated primarily by money and survival. Is not intimidated by others larger than him. Despite this exterior, secretly feels for his companions and does the right thing in the end.
Ronan/Scorpius - Singular being of immense strength. Bears deep, racial hatred toward a people and single-mindedly seeks their annihilation, despite attempts at peace.
Overall - Group of prisoners unexpectedly thrust together during an attempt at escape. Despite their differences, different goals, and mutual distrust, they come to care for one another and band together against a common foe to prevent galactic domination.
