The Thinker is a custom minifigure from the Justice Society of America theme.
Clifford DeVoe, A.K.A. the Thinker, was a genius criminal whose special helmet, the "thinking cap", gave him telekinesis and mind control powers. After DeVoe's death due to old age, the Thinking Cap was used to create a new security system based on his mind for the Justice Society headquarters. Revived in this A.I. form, the Thinker betrayed the JSA to help his old teammates, the Injustice Society.