In Invincible, Robot was a rather mysterious figure. He was initially part of the Teen Team, who later joined and was appointed the leader of the new Guardians of the Globe after the previous guardians died. Throughout the series, we see that he is scheming some plan with the Mauler Twins, aiding their escape from prison. It was later revealed that the robot was controlled by a human who suffered serious deformations and illness. He was then aided by the twins to artificially create a body made from his team member’s, Rex Splode’s, blood. The twins then help transfer his consciousness from the original body to this new one.

Correction

Um actually … His consciousness is not transferred to the new body. It was duplicated over to the new body, and the original died of its illness.