Humberto Lopez desperately wants to find his missing parents and hopes his powers and training will help to accomplish this. He is part boy, part dinosaur, all hero. He is Reptil.
Reptil's career with the Initiative began after Stegron led a series of attacks on several S.H.I.E.L.D. bases, using reanimated dinosaurs for his army. It was determined Reptil's unique power set would be key in ending the assaults. Indeed he was able to locate Stegron, but his impulsive actions allowed the villain to escape and one of his team to be harmed. If not for Tigra sticking her neck out for him, Reptil would have been ejected from the group.
Mission of Mercy
Reptil desperately wanted to be a hero and stay in the Initiative, so he could use their resources to locate his missing parents. Tigra did her best to show him what it means to be a hero, and Reptil would soon be able to test her theory. After finding Stegron a second time with a more favorable outcome, the Initiative found out what the dinosaur-man was looking for. During the war Hulk waged in Manhattan, the Heroes for Hire were sent to the Savage Land to retrieve Moon Boy for S.H.I.E.L.D. Since that time Moon Boy’s companion, Devil Dinosaur, was beginning to suffer from severe depression and his health was in decline. Stegron merely wanted to reunite the two before another dinosaur's life was taken by humans.
Reptil felt strongly about Moon Boy's captivity, and Tigra gave him a choice. Making up a fabricated story of how a dinosaur ate Moon Boy, Tigra secretly helped liberate him, and Reptil carried him away. The choice Reptil made was to be thrown out of the Initiative to save Moon Boy, but Reptil proved he could be a hero by making the sacrifice. Tigra contacted Ka-Zar, and Moon Boy was taken back to the Savage Land. Reptil accompanied them, and Ka-Zar made a promise that he would help find Reptil's parents.
After the Initiative was disbanded, Reptil was brought back to the Avengers Academy where he and five others were chosen to be heroes-in-training. He was enthusiastic about the opportunity, but he soon found out why he was asked to join. Those in charge of the academy wanted to make sure Reptil wouldn't succumb to all the pain in his life and use his powers for criminal behavior. He eventually impressed his teachers enough to be voted class leader, but during an incident to capture Mentallo, Reptil lost control when he transformed into a Velociraptor. No one but Mentallo was injured, but Reptil was asked to speak with Jessica Jones about his repressed anger to avoid another potentially dangerous episode.
All Grown Up
Reptil was witness to the Avengers defeat at the hands of Korvac and he hid with his classmates, Jocasta, and Korvac's ex-wife, Carina in a room inside the Infinite Avengers Mansion. Carina knew it was only a matter of time before Korvac found them, so she pulled Reptil's future self from somewhere in the timestream, implanting the younger Reptil's mind within. Reptil now had the power he was destined for and the ability to stand up to Korvac, and he did so in the full form of a Tyrannosaurus Rex. After Korvac was defeated, Carina restored all the students back to their younger selves, but Reptil wanted to retain his enhanced powers and chose to remain as an adult, making it impossible for Carina to switch him back.