Origin
Elizabeth Dehner was a Psychiatrist aboard the U.S.S. Enterprise. While on a mission exploring the galactic barrier, she and the Enterprise Crew were hit by radiation that gave her and Gary Mitchell superhuman abilities due to their high ESP ratings. Gary became mad with power and Dehner was forced to destroy him at the cost of her own life.
Creation
Elizabeth Dehner was created for the second pilot episode of the original Star Trek television show.