As a senior at the University of Buffalo, Tom fell in with a group of cultists. Learning that they were planning to actually summon a demon, he tried to stop them and wound up as the human sacrifice. The summoning went awry and Tom awoke bound to the demon with the cultists dead around him. To atone for what his demon half had done, he became the superhero The Bat.
While Tom was in full control most of the time, in extreme situations, the demon would surface and he would become violent and ruthless. In August 1969, the Squad's foe The Sorceress caused Tom's demon side to take full control and The Bat became an ally of the villainess. However, on Halloween 1971, as the Sorceress was about to sacrifice the Squad, Tom managed to regain control and save his former teammates but at the cost of his own life.