Disambiguation: Robert Crane / Paul Dennis
First published in: 1942
The original Robotman (Robert Crane/Paul Dennis) first appeared in Star Spangled Comics (DC, 1941 series) #7 (April 1942). Decades later, his brain was transplanted into the body of Chuck Grayson, as shown in DC Comics Presents (DC, 1978 series) #31 (March 1981).
Link: https://en.wikipedia.org/wiki/Robotman_(Robert_Crane)