Brainchild was one of Magneto's first Savage Land Mutates, and was involved in the Mutates subsequent activities. Whenever the Mutates lacked a leader, Brainchild filled that role. Presumably, Brainchild remained with the Mutates in the Savage Land, leading them in the stead of Zaladane. He rarely attacked directly in combat, preferring to strike by surprise because of his relatively weak physical stature.
Several times, using the Savage Land Mutate, Brainchild tried do conquer the Savage Land. In one of these, using a device designed by Magneto, he tried to make Ka-zar kill Deadpool, but was eventually deceived. While trying to escape, Deadpool shot his pterodactylus, making him fall - apparently have been eaten by dinosaurs.