Origin

Hank Hensley was a veteran of the US military. After Flash Thompson was resurrected, they became friends when they started volunteering for the same homeless shelter. In addition to his volunteer work, Hank was also looking into a security profession.

Creation

Hank Hensley first appeared in Extreme Carnage: Alpha by Phillip Kennedy Johnson and Manuel Garcia.

Major Story Arcs

Extreme Carnage

After Flash tracked Carnage to the political campaign of Senator Peter Krane, he recruited Hank to get a job on Krane's security detail so that he could inform on Krane to Flash. Hank was unaware of both Krane and Flash's connection to symbiotes at first nor was he aware of the symbiote, Sleeper, that had secretly bonded to him on Flash's instructions, to keep Hank safe.

After informing to Flash and his symbiote team and learning their true nature, he returned to the campaign to continue spying. Unfortunately, he was followed by Agony and her new host and was outed to Carnage, who was actually bonded to Sen. Krane's son, Arthur. He was impaled on a spike from Carnage causing him to seemingly dead. Thankfully, he was just unconscious as Sleeper held him together, eventually taking over his body to fight Riot.

With Flash and his new team brought in to fight Carnage and the other Life Foundation Five symbiotes in his employ, Sleeper agreed to secretly stay bonded to Hank until he was fully healed, with Hank none the wiser.

Sleeper Agent

After Hank had fully recovered, Sleeper silently disconnected from Hank and moved in with the Brocks. With Eddie Brock off in space, Dylan Brock kidnapped by Life Foundation, and the Venom symbiote in hiding, Sleeper decided to activate a small part of him that he kept connected to Hank as his Sleeper Agent. Sleeper essentially puppeteered his body to Life Foundation, where his biochemistry abilities made most of Life Foundation's anti-symbiote defenses worthless against him. He easily recovered Dylan's comatose body and escaped on a helicopter flown by one of Eddie's old contacts, Archer Lyle. Together, they reunited Dylan with an injured Venom, transforming themselves into a new being, named Codex, revealing Dylan to be half symbiote in nature. As such, he disconnects Sleeper from the hivemind, as he will need an army of symbiotes to save his father.