Terra-X is the supposed Daughter of Dare, Slade Murdock, and was a founding member of the New Mutant Titans. She later joins the X-Patrol sometime after their first mission, but eventually betrays the team to their enemy, X-Stroke the Eliminator. After the X-Patrol manages to defeat X-Stroke, Terra-X escapes to Zenosha, where she is attacked and killed by the alien Brood.
Terra-X is later resurrected by Brother Brood, and becomes a willing member of his cult. Although sent to attack the X-Patrol as a whole, her main target is Beastling, her former love-interest. Terra-X is stopped from killing Jericho when Elasti-Girl flies into her ear-canal and put Terra-X out of action.