Nebula is a Luphomoid assassin, an adopted daughter of the intergalactic warlord, Thanos and adopted sister of Gamora. As the right-hand woman of Ronan the Accuser during his and Thanos' quest to retrieve the Orb, she helped him in the fight against the planet Xandar and the Guardians of the Galaxy.
Portrayed by: Karen Gillan
Nebula vanished after a fight against her sister. Nebula soon was captured by the Sovereign and handed back to the Guardians. She escaped and helped Taserface lead the other Ravagers in a mutiny against their former leader Yondu Udonta before leaving to find and kill Gamora.
After forgiving and helping her own sister alongside the Guardians during the Battle on Ego's Planet, she left in a ship to pursue a revenge mission against Thanos.
Avengers: Infinity War
Nebula was eventually captured by Thanos and used as a bargaining tool to convince Gamora to reveal the location of the Soul Stone. Escaping and then pursuing Thanos to Titan, Nebula learned that Thanos had killed Gamora and aided both the Guardians and the Avengers in combating Thanos.
Despite their efforts, they failed to stop Thanos from obtaining the Infinity Stones, which he then used to wipe out half the universe's population. Nebula was among those who survived, but was left alone on Titan with Tony Stark.
She and Rocket Raccoon are currently the remaining members of the Guardians of the Galaxy.