After Spider-Man unexpectedly ate the Rhino, the Fantastic Four subdued him and put him in a cage for examination. Reed Richards gathered together a team of scientists, and it wasn't long before they discovered that Spider-Man was infected with a virus that altered his DNA, making him more predatorial and giving him a desire for human meat.
As Reed continued to study the plague, Ben eventually turned and freed Spider-Man from his cage, though his motives are unknown. At the same time Red She-Hulk was rampaging in the lobby of the Baxter Building. Together, they allied themselves with Thundra and destroyed the Baxter Building. Wolverine and the Punisher came to their rescue, but Ben and Thundra were able to escape.
They eventually found the infected Hulk formed an alliance with him so that they can kill the scientists trying to cure them. Hulk agreed and tracked the convoy of escaping scientists to the Goethals Bridge, where his army of cannibals fought an army of heroes that acted as distractions while the scientists escaped.
The Hulk and Thing's army grew larger and larger, which they used to hunt for the scientists. The Hulk went off on his own, leaving Captain America and the Punisher to fight Thing and his army. The Punisher blew up the surrounding area, supposedly destroying the army, but Thing seemingly escaped.
At some point, Thing formed a tribe within the Baxter Building, killing many heroes over time. After nearly a year of thinking of a way to kill him, the Punisher used high explosive armor piercing missiles to destroy the Baxter Building, killing Ben. His head was seen among the Punisher's collection of severed heads.
Seemingly those of Benjamin Grimm (Earth-616)#Powers.
Due to his exposure to Survivor 118, Thing was capable of adapting to extreme changes in his environment.