His mutant physiology granting him a great stature and physical prowess, Matonabbe had always been ridiculed by the townsfolk for his "half-breed" status. Somehow, Matonabbe came to the attention of Pixie, a member of the race of Eternals who was looking for adventure among humans & a
crime-fighting partner, she chose Matonabbe after watching how he dealt with those who would ridicule him.
Determined to make him her partner, Pixie convinced him to use his powers as a crime fighter. Together, the two became known as Oxbow and Pixie and were later asked to join the premier superhero team of their generation, the First Line. Over time, Pixie & Sam developed a romantic relationship and were rarely seen apart. Pixie and Oxbow were among the members of the First Line assembled for its final mission, defeating an invasion by the alien Skrulls. Matonabbe was killed in the battle.