Not much is yet known about the man that would become Weapon H, except that his name is Clayton and that he is a former soldier, who was apparently kidnapped by the Weapon X Program.
What is known is that he is a former soldier, is married to Sonia Sung, and has a young son and daughter.
Weapon H was created by Greg Pak, Mike Deadato Jr (design) and first drawn by Robert Gill and first appeared in The Totally Awesome Hulk issue 22 (2017). His silhouette, however, already made cameo appearances in Totally Awesome Hulk 21 and Weapon X Vol. 3 issue 7.
Major Story Arc
Taken by Weapon X
At some point after Clayton was discharged by the military, he worked for Eaglestar International. On one mission, he killed his fellow troops to stop them from perpetuating war-crimes against the villagers of Ujanka for sabotaging a pipeline owned and operated by Roxxon. As punishment, Clayton was sold to the Weapon X program and was experimented on as part of the Batch-H division that was focused on creating hybrid mutant-killing cyborgs using DNA from both Hulk and Wolverine.
Becoming Weapon H
Unlike the other test subjects in Batch-H, Clayton was not a believer and treated differently. Dr. Alba left more of Clayton's brain, hoping it would increase the chances of training him. When the Hulk and a the Weapon-X strike team attacked the Weapon X headquarters, Clayton, now designated H-Alpha, attacked the intruders as part of his programming. He also decapitated another one of the program's creations, H-Beta. Once the Weapon X staff escaped the rampage, Clayton ceased fighting in order to escape.
Hiding his Past
After his escape from Hulk and Weapon X, Clayton attacked every branch of Eaglestar in order to destroy all data about him so no one, like Weapon X's director William Stryker, would leave his family - that he could only barely remember - alone. It was while Clayton was doing this that he was brought back under the control of Dr. Alba, thanks to being injected by nanites that could reset his command settings. Dr. Alba then used this control to order Weapon H to prove his power by killing the entire population of Phoenix, Arizona. Wolverine and the Weapon X mutant team were able to break Dr. Alba's control over him and Clayton resumed his mission of keeping his family safe from those who sought to use them against him.
War of the Realms
During Malekith's plan and overall takeover of the nine realms, he made a deal with Roxxon's leader to help fight against the bloodthirsty inhabitants of Weirdworld. After a brief fight with Man-Thing, the two, along with Korg, the three of them traveled to Weirdworld. While Roxxon wanted them to kill everything, Clayton, Man-Thing, and Korg decided to help them. After being captured by one of their inhabitants, Clayton accidentally destroyed the barrier protecting the world from the monsters. After a long fight, they discover the source of Weirdworlds power, Morgan Le Fay.