Origin 

A resident of Cape Town, South Africia, Cornell Gray was identified on Nick Fury's list of Caterpillars, a record of untapped superhumans he could use if necessary. Gray was recruited into the Secret Warriors and placed on Team Black, a team of the most dangerous and unruly Caterpillars under the command of Alexander Pierce. 

Creation 

Cornell Gray  was created by Jonathan Hickman  and first illustrated by Alessandro Vitti in Secret Warriors.  The character was first mentioned in the back matter of the first issue of Secret Warriors,  which featured Nick Fury's list of Caterpillars. Gray did not actually appear until midway into the series, where Team Black appeared for one story arc.  

Major Story Arcs 

Last Ride of the Howling Commandos 

Cornell Gray  and the rest of Team Black were deployed to take part in a joint attack on HYDRA's  Hell's Heaven base in China along with the Howling Commandos PMC.  The operation was a success with Team Black taking point on the infiltration of the base, allowing for a bomb to be detonated inside that reduced it all to burning rubble. With their mission complete, Team Black made their own separate exit from China apart from the Howling Commandos, not realizing that the Howling Commandos would suffer a devastating battle against HYDRA forces after they left. 

Wheels Within Wheels  

Having won his secret war against HYDRA and Leviathan, Nick Fury pulled together all of the surviving members of the Secret Warriors and Howling Commandos together into a new organization sponsored by the United Nations. This included Wolfe and the rest of Team Black, who now served in this organization under the overall command of Daisy Johnson.

Powers and Abilities 

Described as having a parasitic brain, Cornell Gray hides mouth-like growths on the palms of his bandaged hands. It is a mutation similar to Emplate's, though there is no known connection to Emplate nor is it implied that Gray is a mutant. His parasitic ability allows him to pull information out of sentient beings, and there are perhaps other abilities yet to be shown. 
 
Presumably, Gray has received the same training in espionage and combat as other members of the Secret Warriors.